diff --git a/Sources/System/FilePath/FilePath.swift b/Sources/System/FilePath/FilePath.swift
index c1dfd7f3..5668405f 100644
--- a/Sources/System/FilePath/FilePath.swift
+++ b/Sources/System/FilePath/FilePath.swift
@@ -41,18 +41,18 @@
 public struct FilePath {
   // TODO(docs): Section on all the new syntactic operations, lexical normalization, decomposition,
   // components, etc.
-  internal var _storage: SystemString
+  internal var _storage: _SystemString
 
   /// Creates an empty, null-terminated path.
   public init() {
-    self._storage = SystemString()
+    self._storage = _SystemString()
     _invariantCheck()
   }
 
   // In addition to the empty init, this init will properly normalize
   // separators. All other initializers should be implemented by
   // ultimately deferring to a normalizing init.
-  internal init(_ str: SystemString) {
+  internal init(_ str: _SystemString) {
     self._storage = str
     self._normalizeSeparators()
     _invariantCheck()
diff --git a/Sources/System/FilePath/FilePathComponentView.swift b/Sources/System/FilePath/FilePathComponentView.swift
index efdd084a..90168256 100644
--- a/Sources/System/FilePath/FilePathComponentView.swift
+++ b/Sources/System/FilePath/FilePathComponentView.swift
@@ -30,7 +30,7 @@ extension FilePath {
   ///     // path is "/home/username/bin/scripts/tree"
   public struct ComponentView {
     internal var _path: FilePath
-    internal var _start: SystemString.Index
+    internal var _start: _SystemString.Index
 
     internal init(_ path: FilePath) {
       self._path = path
@@ -50,7 +50,7 @@ extension FilePath {
       // TODO(perf): Small-form root (especially on Unix). Have Root
       // always copy out (not worth ref counting). Make sure that we're
       // not needlessly sliding values around or triggering a COW
-      let rootStr = self.root?._systemString ?? SystemString()
+      let rootStr = self.root?._systemString ?? _SystemString()
       var comp = ComponentView(self)
       self = FilePath()
       defer {
@@ -73,7 +73,7 @@ extension FilePath {
       // TODO(perf): Small-form root (especially on Unix). Have Root
       // always copy out (not worth ref counting). Make sure that we're
       // not needlessly sliding values around or triggering a COW
-      let rootStr = self.root?._systemString ?? SystemString()
+      let rootStr = self.root?._systemString ?? _SystemString()
       var comp = ComponentView(self)
       self = FilePath()
       defer {
@@ -92,7 +92,7 @@ extension FilePath {
 extension FilePath.ComponentView: BidirectionalCollection {
   public typealias Element = FilePath.Component
   public struct Index: Comparable, Hashable {
-    internal typealias Storage = SystemString.Index
+    internal typealias Storage = _SystemString.Index
 
     internal var _storage: Storage
 
@@ -159,7 +159,7 @@ extension FilePath.ComponentView: RangeReplaceableCollection {
     // filling in the bytes ourselves.
 
     // If we're inserting at the end, we need a leading separator.
-    var str = SystemString()
+    var str = _SystemString()
     let atEnd = subrange.lowerBound == endIndex
     if atEnd {
       str.append(platformSeparator)
@@ -178,7 +178,7 @@ extension FilePath {
   public init<C: Collection>(
     root: Root?, _ components: C
   ) where C.Element == Component {
-    var str = root?._systemString ?? SystemString()
+    var str = root?._systemString ?? _SystemString()
     str.appendComponents(components: components)
     self.init(str)
   }
@@ -191,7 +191,7 @@ extension FilePath {
   /// Create a file path from an optional root and a slice of another path's
   /// components.
   public init(root: Root?, _ components: ComponentView.SubSequence) {
-    var str = root?._systemString ?? SystemString()
+    var str = root?._systemString ?? _SystemString()
     let (start, end) =
       (components.startIndex._storage, components.endIndex._storage)
     str.append(contentsOf: components.base._slice[start..<end])
@@ -203,11 +203,11 @@ extension FilePath {
 
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
 extension FilePath.ComponentView: _PathSlice {
-  internal var _range: Range<SystemString.Index> {
+  public var _range: Range<_SystemString.Index> {
     _start ..< _path._storage.endIndex
   }
 
-  internal init(_ str: SystemString) {
+  public init(_ str: _SystemString) {
     fatalError("TODO: consider dropping proto req")
   }
 }
@@ -216,7 +216,7 @@ extension FilePath.ComponentView: _PathSlice {
 
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
 extension FilePath.ComponentView {
-  internal func _invariantCheck() {
+  public func _invariantCheck() {
     #if DEBUG
     if isEmpty {
       precondition(_path.isEmpty == (_path.root == nil))
diff --git a/Sources/System/FilePath/FilePathComponents.swift b/Sources/System/FilePath/FilePathComponents.swift
index ecd713ea..b8d47e45 100644
--- a/Sources/System/FilePath/FilePathComponents.swift
+++ b/Sources/System/FilePath/FilePathComponents.swift
@@ -30,9 +30,9 @@ extension FilePath {
   ///   * `\\?\Volume{12345678-abcd-1111-2222-123445789abc}\`
   public struct Root {
     internal var _path: FilePath
-    internal var _rootEnd: SystemString.Index
+    internal var _rootEnd: _SystemString.Index
 
-    internal init(_ path: FilePath, rootEnd: SystemString.Index) {
+    internal init(_ path: FilePath, rootEnd: _SystemString.Index) {
       self._path = path
       self._rootEnd = rootEnd
       _invariantCheck()
@@ -56,14 +56,14 @@ extension FilePath {
   ///     path.append(file)               // path is "/tmp/foo.txt"
   public struct Component {
     internal var _path: FilePath
-    internal var _range: Range<SystemString.Index>
+    public var _range: Range<_SystemString.Index>
 
     // TODO: Make a small-component form to save on ARC overhead when
     // extracted from a path, and especially to save on allocation overhead
     // when constructing one from a String literal.
 
     internal init<RE: RangeExpression>(_ path: FilePath, _ range: RE)
-    where RE.Bound == SystemString.Index {
+    where RE.Bound == _SystemString.Index {
       self._path = path
       self._range = range.relative(to: path._storage)
       precondition(!self._range.isEmpty, "FilePath components cannot be empty")
@@ -104,7 +104,7 @@ extension FilePath.Root {
 
 // MARK: - Internals
 
-extension SystemString {
+extension _SystemString {
   // TODO: take insertLeadingSlash: Bool
   // TODO: turn into an insert operation with slide
   internal mutating func appendComponents<C: Collection>(
@@ -127,21 +127,21 @@ extension SystemString {
 
 // Unifying protocol for common functionality between roots, components,
 // and views onto SystemString and FilePath.
-internal protocol _StrSlice: _PlatformStringable, Hashable, Codable {
-  var _storage: SystemString { get }
-  var _range: Range<SystemString.Index> { get }
+public protocol _StrSlice: _PlatformStringable, Hashable, Codable {
+  var _storage: _SystemString { get }
+  var _range: Range<_SystemString.Index> { get }
 
-  init?(_ str: SystemString)
+  init?(_ str: _SystemString)
 
   func _invariantCheck()
 }
 extension _StrSlice {
-  internal var _slice: Slice<SystemString> {
+  internal var _slice: Slice<_SystemString> {
     Slice(base: _storage, bounds: _range)
   }
 
   internal func _withSystemChars<T>(
-    _ f: (UnsafeBufferPointer<SystemChar>) throws -> T
+    _ f: (UnsafeBufferPointer<_SystemChar>) throws -> T
   ) rethrows -> T {
     try _storage.withSystemChars {
       try f(UnsafeBufferPointer(rebasing: $0[_range]))
@@ -153,17 +153,17 @@ extension _StrSlice {
     try _slice.withCodeUnits(f)
   }
 
-  internal init?(_platformString s: UnsafePointer<CInterop.PlatformChar>) {
-    self.init(SystemString(platformString: s))
+  public init?(_platformString s: UnsafePointer<CInterop.PlatformChar>) {
+    self.init(_SystemString(platformString: s))
   }
 
-  internal func _withPlatformString<Result>(
+  public func _withPlatformString<Result>(
     _ body: (UnsafePointer<CInterop.PlatformChar>) throws -> Result
   ) rethrows -> Result {
     try _slice.withPlatformString(body)
   }
 
-  internal var _systemString: SystemString { SystemString(_slice) }
+  internal var _systemString: _SystemString { _SystemString(_slice) }
 }
 extension _StrSlice {
   public static func == (lhs: Self, rhs: Self) -> Bool {
@@ -180,7 +180,7 @@ internal protocol _PathSlice: _StrSlice {
   var _path: FilePath { get }
 }
 extension _PathSlice {
-  internal var _storage: SystemString { _path._storage }
+  public var _storage: _SystemString { _path._storage }
 }
 
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
@@ -188,19 +188,19 @@ extension FilePath.Component: _PathSlice {
 }
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
 extension FilePath.Root: _PathSlice {
-  internal var _range: Range<SystemString.Index> {
+  public var _range: Range<_SystemString.Index> {
     (..<_rootEnd).relative(to: _path._storage)
   }
 }
 
 @available(/*System 0.0.1: macOS 11.0, iOS 14.0, watchOS 7.0, tvOS 14.0*/iOS 8, *)
 extension FilePath: _PlatformStringable {
-  func _withPlatformString<Result>(_ body: (UnsafePointer<CInterop.PlatformChar>) throws -> Result) rethrows -> Result {
+  public func _withPlatformString<Result>(_ body: (UnsafePointer<CInterop.PlatformChar>) throws -> Result) rethrows -> Result {
     try _storage.withPlatformString(body)
   }
 
-  init(_platformString: UnsafePointer<CInterop.PlatformChar>) {
-    self.init(SystemString(platformString: _platformString))
+  public init(_platformString: UnsafePointer<CInterop.PlatformChar>) {
+    self.init(_SystemString(platformString: _platformString))
   }
 
 }
@@ -208,7 +208,7 @@ extension FilePath: _PlatformStringable {
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
 extension FilePath.Component {
   // The index of the `.` denoting an extension
-  internal func _extensionIndex() -> SystemString.Index? {
+  internal func _extensionIndex() -> _SystemString.Index? {
     guard kind == .regular,
           let idx = _slice.lastIndex(of: .dot),
           idx != _slice.startIndex
@@ -217,26 +217,26 @@ extension FilePath.Component {
     return idx
   }
 
-  internal func _extensionRange() -> Range<SystemString.Index>? {
+  internal func _extensionRange() -> Range<_SystemString.Index>? {
     guard let idx = _extensionIndex() else { return nil }
     return _slice.index(after: idx) ..< _slice.endIndex
   }
 
-  internal func _stemRange() -> Range<SystemString.Index> {
+  internal func _stemRange() -> Range<_SystemString.Index> {
     _slice.startIndex ..< (_extensionIndex() ?? _slice.endIndex)
   }
 }
 
-internal func _makeExtension(_ ext: String) -> SystemString {
-  var result = SystemString()
+internal func _makeExtension(_ ext: String) -> _SystemString {
+  var result = _SystemString()
   result.append(.dot)
-  result.append(contentsOf: ext.unicodeScalars.lazy.map(SystemChar.init))
+  result.append(contentsOf: ext.unicodeScalars.lazy.map(_SystemChar.init))
   return result
 }
 
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
 extension FilePath.Component {
-  internal init?(_ str: SystemString) {
+  public init?(_ str: _SystemString) {
     // FIXME: explicit null root? Or something else?
     let path = FilePath(str)
     guard path.root == nil, path.components.count == 1 else {
@@ -249,7 +249,7 @@ extension FilePath.Component {
 
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
 extension FilePath.Root {
-  internal init?(_ str: SystemString) {
+  public init?(_ str: _SystemString) {
     // FIXME: explicit null root? Or something else?
     let path = FilePath(str)
     guard path.root != nil, path.components.isEmpty else {
@@ -265,7 +265,7 @@ extension FilePath.Root {
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
 extension FilePath.Component {
   // TODO: ensure this all gets easily optimized away in release...
-  internal func _invariantCheck() {
+  public func _invariantCheck() {
     #if DEBUG
     precondition(!_slice.isEmpty)
     precondition(_slice.last != .null)
@@ -277,7 +277,7 @@ extension FilePath.Component {
 
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
 extension FilePath.Root {
-  internal func _invariantCheck() {
+  public func _invariantCheck() {
     #if DEBUG
     precondition(self._rootEnd > _path._storage.startIndex)
 
diff --git a/Sources/System/FilePath/FilePathParsing.swift b/Sources/System/FilePath/FilePathParsing.swift
index 6d014774..eb18455b 100644
--- a/Sources/System/FilePath/FilePathParsing.swift
+++ b/Sources/System/FilePath/FilePathParsing.swift
@@ -11,30 +11,30 @@
 // manages (and hides) the null terminator
 
 // The separator we use internally
-private var genericSeparator: SystemChar { .slash }
+private var genericSeparator: _SystemChar { .slash }
 
 // The platform preferred separator
 //
 // TODO: Make private
-internal var platformSeparator: SystemChar {
+internal var platformSeparator: _SystemChar {
   _windowsPaths ? .backslash : genericSeparator
 }
 
 // Whether the character is the canonical separator
 // TODO: Make private
-internal func isSeparator(_ c: SystemChar) -> Bool {
+internal func isSeparator(_ c: _SystemChar) -> Bool {
   c == platformSeparator
 }
 
 // Whether the character is a pre-normalized separator
-internal func isPrenormalSeparator(_ c: SystemChar) -> Bool {
+internal func isPrenormalSeparator(_ c: _SystemChar) -> Bool {
   c == genericSeparator || c == platformSeparator
 }
 
 // Separator normalization, checking, and root parsing is internally hosted
 // on SystemString for ease of unit testing.
 
-extension SystemString {
+extension _SystemString {
   // For invariant enforcing/checking. Should always return false on
   // a fully-formed path
   fileprivate func _hasTrailingSeparator() -> Bool {
@@ -186,7 +186,7 @@ extension FilePath {
   }
 }
 
-extension SystemString {
+extension _SystemString {
   internal var _relativePathStart: Index {
     _parseRoot().relativeBegin
   }
@@ -194,7 +194,7 @@ extension SystemString {
 
 @available(/*System 0.0.1: macOS 11.0, iOS 14.0, watchOS 7.0, tvOS 14.0*/iOS 8, *)
 extension FilePath {
-  internal var _relativeStart: SystemString.Index {
+  internal var _relativeStart: _SystemString.Index {
     _storage._relativePathStart
   }
   internal var _hasRoot: Bool {
@@ -206,7 +206,7 @@ extension FilePath {
 
 @available(/*System 0.0.1: macOS 11.0, iOS 14.0, watchOS 7.0, tvOS 14.0*/iOS 8, *)
 extension FilePath {
-  internal typealias _Index = SystemString.Index
+  internal typealias _Index = _SystemString.Index
 
   // Parse a component that starts at `i`. Returns the end
   // of the component and the start of the next. Parsing terminates
@@ -271,12 +271,12 @@ extension FilePath {
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
 extension FilePath.ComponentView {
   // TODO: Store this...
-  internal var _relativeStart: SystemString.Index {
+  internal var _relativeStart: _SystemString.Index {
     _path._relativeStart
   }
 }
 
-extension SystemString {
+extension _SystemString {
   internal func _parseRoot() -> (
     rootEnd: Index, relativeBegin: Index
   ) {
@@ -303,7 +303,7 @@ extension FilePath.Root {
   //
   // TODO: public
   internal var isAbsolute: Bool {
-    assert(FilePath(SystemString(self._slice)).root == self, "not a root")
+    assert(FilePath(_SystemString(self._slice)).root == self, "not a root")
 
     guard _windowsPaths else { return true }
 
@@ -354,8 +354,8 @@ extension FilePath {
 
   // Perform an append, inseting a separator if needed.
   // Note that this will not check whether `content` is a root
-  internal mutating func _append(unchecked content: Slice<SystemString>) {
-    assert(FilePath(SystemString(content)).root == nil)
+  internal mutating func _append(unchecked content: Slice<_SystemString>) {
+    assert(FilePath(_SystemString(content)).root == nil)
     if content.isEmpty { return }
     if _needsSeparatorForAppend {
       _storage.append(platformSeparator)
diff --git a/Sources/System/FilePath/FilePathString.swift b/Sources/System/FilePath/FilePathString.swift
index 4fe9c1fd..a14cae7a 100644
--- a/Sources/System/FilePath/FilePathString.swift
+++ b/Sources/System/FilePath/FilePathString.swift
@@ -302,7 +302,7 @@ extension FilePath: ExpressibleByStringLiteral {
   /// - Parameter string: A string
   ///   whose Unicode encoded contents to use as the contents of the path.
   public init(_ string: String) {
-    self.init(SystemString(string))
+    self.init(_SystemString(string))
   }
 }
 
@@ -327,7 +327,7 @@ extension FilePath.Component: ExpressibleByStringLiteral {
   /// Returns `nil` if `string` is empty, a root, or has more than one component
   /// in it.
   public init?(_ string: String) {
-    self.init(SystemString(string))
+    self.init(_SystemString(string))
   }
 }
 
@@ -350,7 +350,7 @@ extension FilePath.Root: ExpressibleByStringLiteral {
   ///
   /// Returns `nil` if `string` is empty or is not a root.
   public init?(_ string: String) {
-    self.init(SystemString(string))
+    self.init(_SystemString(string))
   }
 }
 
diff --git a/Sources/System/FilePath/FilePathSyntax.swift b/Sources/System/FilePath/FilePathSyntax.swift
index 1c3fc097..a9ccdecf 100644
--- a/Sources/System/FilePath/FilePathSyntax.swift
+++ b/Sources/System/FilePath/FilePathSyntax.swift
@@ -320,11 +320,11 @@ extension FilePath {
       defer { _invariantCheck() }
       guard let base = lastComponent, base.kind == .regular else { return }
 
-      let suffix: SystemString
+      let suffix: _SystemString
       if let ext = newValue {
         suffix = _makeExtension(ext)
       } else {
-        suffix = SystemString()
+        suffix = _SystemString()
       }
 
       let extRange = (
diff --git a/Sources/System/FilePath/FilePathWindows.swift b/Sources/System/FilePath/FilePathWindows.swift
index b725dd17..ac1332e8 100644
--- a/Sources/System/FilePath/FilePathWindows.swift
+++ b/Sources/System/FilePath/FilePathWindows.swift
@@ -8,24 +8,24 @@
 */
 
 internal struct _ParsedWindowsRoot {
-  var rootEnd: SystemString.Index
+  var rootEnd: _SystemString.Index
 
   // TODO: Remove when I normalize to always (except `C:`)
   // have trailing separator
-  var relativeBegin: SystemString.Index
+  var relativeBegin: _SystemString.Index
 
-  var drive: SystemChar?
+  var drive: _SystemChar?
   var fullyQualified: Bool
 
-  var deviceSigil: SystemChar?
+  var deviceSigil: _SystemChar?
 
-  var host: Range<SystemString.Index>?
-  var volume: Range<SystemString.Index>?
+  var host: Range<_SystemString.Index>?
+  var volume: Range<_SystemString.Index>?
 }
 
 extension _ParsedWindowsRoot {
   static func traditional(
-    drive: SystemChar?, fullQualified: Bool, endingAt idx: SystemString.Index
+    drive: _SystemChar?, fullQualified: Bool, endingAt idx: _SystemString.Index
   ) -> _ParsedWindowsRoot {
     _ParsedWindowsRoot(
       rootEnd: idx,
@@ -38,11 +38,11 @@ extension _ParsedWindowsRoot {
   }
 
   static func unc(
-    deviceSigil: SystemChar?,
-    server: Range<SystemString.Index>,
-    share: Range<SystemString.Index>,
-    endingAt end: SystemString.Index,
-    relativeBegin relBegin: SystemString.Index
+    deviceSigil: _SystemChar?,
+    server: Range<_SystemString.Index>,
+    share: Range<_SystemString.Index>,
+    endingAt end: _SystemString.Index,
+    relativeBegin relBegin: _SystemString.Index
   ) -> _ParsedWindowsRoot {
     _ParsedWindowsRoot(
       rootEnd: end,
@@ -55,10 +55,10 @@ extension _ParsedWindowsRoot {
   }
 
   static func device(
-    deviceSigil: SystemChar,
-    volume: Range<SystemString.Index>,
-    endingAt end: SystemString.Index,
-    relativeBegin relBegin: SystemString.Index
+    deviceSigil: _SystemChar,
+    volume: Range<_SystemString.Index>,
+    endingAt end: _SystemString.Index,
+    relativeBegin relBegin: _SystemString.Index
   ) -> _ParsedWindowsRoot {
     _ParsedWindowsRoot(
       rootEnd: end,
@@ -72,13 +72,13 @@ extension _ParsedWindowsRoot {
 }
 
 struct _Lexer {
-  var slice: Slice<SystemString>
+  var slice: Slice<_SystemString>
 
-  init(_ str: SystemString) {
+  init(_ str: _SystemString) {
     self.slice = str[...]
   }
 
-  var backslash: SystemChar { .backslash }
+  var backslash: _SystemChar { .backslash }
 
   // Try to eat a backslash, returns false if nothing happened
   mutating func eatBackslash() -> Bool {
@@ -86,7 +86,7 @@ struct _Lexer {
   }
 
   // Try to consume a drive letter and subsequent `:`.
-  mutating func eatDrive() -> SystemChar? {
+  mutating func eatDrive() -> _SystemChar? {
     let copy = slice
     if let d = slice._eat(if: { $0.isLetter }), slice._eat(.colon) != nil {
       return d
@@ -97,7 +97,7 @@ struct _Lexer {
   }
 
   // Try to consume a device sigil (stand-alone . or ?)
-  mutating func eatSigil() -> SystemChar? {
+  mutating func eatSigil() -> _SystemChar? {
     let copy = slice
     guard let sigil = slice._eat(.question) ?? slice._eat(.dot) else {
       return nil
@@ -114,11 +114,11 @@ struct _Lexer {
 
   // Try to consume an explicit "UNC" directory
   mutating func eatUNC() -> Bool {
-    slice._eatSequence("UNC".unicodeScalars.lazy.map { SystemChar(ascii: $0) }) != nil
+    slice._eatSequence("UNC".unicodeScalars.lazy.map { _SystemChar(ascii: $0) }) != nil
   }
 
   // Eat everything up to but not including a backslash or null
-  mutating func eatComponent() -> Range<SystemString.Index> {
+  mutating func eatComponent() -> Range<_SystemString.Index> {
     let backslash = self.backslash
     let component = slice._eatWhile({ $0 != backslash })
       ?? slice[slice.startIndex ..< slice.startIndex]
@@ -129,14 +129,14 @@ struct _Lexer {
     return slice.isEmpty
   }
 
-  var current: SystemString.Index { slice.startIndex }
+  var current: _SystemString.Index { slice.startIndex }
 
   mutating func clear() {
     // TODO: Intern empty system string
-    self = _Lexer(SystemString())
+    self = _Lexer(_SystemString())
   }
 
-  mutating func reset(to: SystemString, at: SystemString.Index) {
+  mutating func reset(to: _SystemString, at: _SystemString.Index) {
     self.slice = to[at...]
   }
 }
@@ -209,7 +209,7 @@ internal struct WindowsRootInfo {
 }
 
 extension _ParsedWindowsRoot {
-  fileprivate func volumeInfo(_ root: SystemString) -> WindowsRootInfo.Volume {
+  fileprivate func volumeInfo(_ root: _SystemString) -> WindowsRootInfo.Volume {
     if let d = self.drive {
       return .drive(Character(d.asciiScalar!))
     }
@@ -223,7 +223,7 @@ extension _ParsedWindowsRoot {
 }
 
 extension WindowsRootInfo {
-  internal init(_ root: SystemString, _ parsed: _ParsedWindowsRoot) {
+  internal init(_ root: _SystemString, _ parsed: _ParsedWindowsRoot) {
     self.volume = parsed.volumeInfo(root)
 
     if let host = parsed.host {
@@ -308,7 +308,7 @@ extension WindowsRootInfo {
 
 }
 
-extension SystemString {
+extension _SystemString {
   // TODO: Or, should I always inline this to remove some of the bookeeping?
   private func _parseWindowsRootInternal() -> _ParsedWindowsRoot? {
     assert(_windowsPaths)
@@ -334,7 +334,7 @@ extension SystemString {
     var lexer = _Lexer(self)
 
     // Helper to parse a UNC root
-    func parseUNC(deviceSigil: SystemChar?) -> _ParsedWindowsRoot {
+    func parseUNC(deviceSigil: _SystemChar?) -> _ParsedWindowsRoot {
       let serverRange = lexer.eatComponent()
       guard lexer.eatBackslash() else {
         fatalError("expected normalized root to contain backslash")
@@ -394,7 +394,7 @@ extension SystemString {
 
   @inline(never)
   internal func _parseWindowsRoot() -> (
-    rootEnd: SystemString.Index, relativeBegin: SystemString.Index
+    rootEnd: _SystemString.Index, relativeBegin: _SystemString.Index
   ) {
     guard let parsed = _parseWindowsRootInternal() else {
       return (startIndex, startIndex)
@@ -403,7 +403,7 @@ extension SystemString {
   }
 }
 
-extension SystemString {
+extension _SystemString {
   // UNC and device roots can have multiple repeated roots that are meaningful,
   // and extra backslashes may need to be inserted for partial roots (e.g. empty
   // volume).
diff --git a/Sources/System/Internals/Exports.swift b/Sources/System/Internals/Exports.swift
index 57abc6fc..9d485bff 100644
--- a/Sources/System/Internals/Exports.swift
+++ b/Sources/System/Internals/Exports.swift
@@ -101,7 +101,7 @@ internal func system_memset(
 
 // Interop between String and platfrom string
 extension String {
-  internal func _withPlatformString<Result>(
+  public func _withPlatformString<Result>(
     _ body: (UnsafePointer<CInterop.PlatformChar>) throws -> Result
   ) rethrows -> Result {
     // Need to #if because CChar may be signed
@@ -112,7 +112,7 @@ extension String {
     #endif
   }
 
-  internal init?(_platformString platformString: UnsafePointer<CInterop.PlatformChar>) {
+  public init?(_platformString platformString: UnsafePointer<CInterop.PlatformChar>) {
     // Need to #if because CChar may be signed
     #if os(Windows)
     guard let strRes = String.decodeCString(
diff --git a/Sources/System/PlatformString.swift b/Sources/System/PlatformString.swift
index 4e2e7ddf..b0a9fd83 100644
--- a/Sources/System/PlatformString.swift
+++ b/Sources/System/PlatformString.swift
@@ -186,7 +186,7 @@ extension CInterop.PlatformUnicodeEncoding.CodeUnit {
   }
 }
 
-internal protocol _PlatformStringable {
+public protocol _PlatformStringable {
   func _withPlatformString<Result>(
     _ body: (UnsafePointer<CInterop.PlatformChar>) throws -> Result
   ) rethrows -> Result
diff --git a/Sources/System/SystemString.swift b/Sources/System/SystemString.swift
index 14651d52..d3145f55 100644
--- a/Sources/System/SystemString.swift
+++ b/Sources/System/SystemString.swift
@@ -8,21 +8,21 @@
 */
 
 // A platform-native character representation, currently used for file paths
-internal struct SystemChar: RawRepresentable, Comparable, Hashable, Codable {
-  internal typealias RawValue = CInterop.PlatformChar
+public struct _SystemChar: RawRepresentable, Comparable, Hashable, Codable {
+  public typealias RawValue = CInterop.PlatformChar
 
-  internal var rawValue: RawValue
+  public var rawValue: RawValue
 
-  internal init(rawValue: RawValue) { self.rawValue = rawValue }
+  public init(rawValue: RawValue) { self.rawValue = rawValue }
 
-  internal init(_ rawValue: RawValue) { self.init(rawValue: rawValue) }
+  public init(_ rawValue: RawValue) { self.init(rawValue: rawValue) }
 
-  static func < (lhs: SystemChar, rhs: SystemChar) -> Bool {
+  public static func < (lhs: _SystemChar, rhs: _SystemChar) -> Bool {
     lhs.rawValue < rhs.rawValue
   }
 }
 
-extension SystemChar {
+extension _SystemChar {
   internal init(ascii: Unicode.Scalar) {
     self.init(rawValue: numericCast(UInt8(ascii: ascii)))
   }
@@ -30,12 +30,12 @@ extension SystemChar {
     self.init(rawValue: codeUnit._platformChar)
   }
 
-  internal static var null: SystemChar { SystemChar(0x0) }
-  internal static var slash: SystemChar { SystemChar(ascii: "/") }
-  internal static var backslash: SystemChar { SystemChar(ascii: #"\"#) }
-  internal static var dot: SystemChar { SystemChar(ascii: ".") }
-  internal static var colon: SystemChar { SystemChar(ascii: ":") }
-  internal static var question: SystemChar { SystemChar(ascii: "?") }
+  internal static var null: _SystemChar { _SystemChar(0x0) }
+  internal static var slash: _SystemChar { _SystemChar(ascii: "/") }
+  internal static var backslash: _SystemChar { _SystemChar(ascii: #"\"#) }
+  internal static var dot: _SystemChar { _SystemChar(ascii: ".") }
+  internal static var colon: _SystemChar { _SystemChar(ascii: ":") }
+  internal static var question: _SystemChar { _SystemChar(ascii: "?") }
 
   internal var codeUnit: CInterop.PlatformUnicodeEncoding.CodeUnit {
     rawValue._platformCodeUnit
@@ -61,13 +61,14 @@ extension SystemChar {
 // A platform-native string representation, currently for file paths
 //
 // Always null-terminated.
-internal struct SystemString {
-  internal typealias Storage = [SystemChar]
+
+public struct _SystemString {
+  public typealias Storage = [_SystemChar]
   internal var nullTerminatedStorage: Storage
 }
 
-extension SystemString {
-  internal init() {
+extension _SystemString {
+  public init() {
     self.nullTerminatedStorage = [.null]
     _invariantCheck()
   }
@@ -85,7 +86,7 @@ extension SystemString {
   }
 
   // Ensures that result is null-terminated
-  internal init<C: Collection>(_ chars: C) where C.Element == SystemChar {
+  internal init<C: Collection>(_ chars: C) where C.Element == _SystemChar {
     var rawChars = Storage(chars)
     if rawChars.last != .null {
       rawChars.append(.null)
@@ -94,7 +95,7 @@ extension SystemString {
   }
 }
 
-extension SystemString {
+extension _SystemString {
   fileprivate func _invariantCheck() {
     #if DEBUG
     precondition(nullTerminatedStorage.last! == .null)
@@ -103,20 +104,20 @@ extension SystemString {
   }
 }
 
-extension SystemString: RandomAccessCollection, MutableCollection {
-  internal typealias Element = SystemChar
-  internal typealias Index = Storage.Index
-  internal typealias Indices = Range<Index>
+extension _SystemString: RandomAccessCollection, MutableCollection {
+  public typealias Element = _SystemChar
+  public typealias Index = Storage.Index
+  public typealias Indices = Range<Index>
 
-  internal var startIndex: Index {
+  public var startIndex: Index {
     nullTerminatedStorage.startIndex
   }
 
-  internal var endIndex: Index {
+  public var endIndex: Index {
     nullTerminatedStorage.index(before: nullTerminatedStorage.endIndex)
   }
 
-  internal subscript(position: Index) -> SystemChar {
+  public subscript(position: Index) -> _SystemChar {
     _read {
       precondition(position >= startIndex && position <= endIndex)
       yield nullTerminatedStorage[position]
@@ -128,42 +129,42 @@ extension SystemString: RandomAccessCollection, MutableCollection {
     }
   }
 }
-extension SystemString: RangeReplaceableCollection {
-  internal mutating func replaceSubrange<C: Collection>(
+extension _SystemString: RangeReplaceableCollection {
+  public mutating func replaceSubrange<C: Collection>(
     _ subrange: Range<Index>, with newElements: C
-  ) where C.Element == SystemChar {
+  ) where C.Element == _SystemChar {
     defer { _invariantCheck() }
     nullTerminatedStorage.replaceSubrange(subrange, with: newElements)
   }
 
-  internal mutating func reserveCapacity(_ n: Int) {
+  public mutating func reserveCapacity(_ n: Int) {
     defer { _invariantCheck() }
     nullTerminatedStorage.reserveCapacity(1 + n)
   }
 
   // TODO: Below include null terminator, is this desired?
 
-  internal func withContiguousStorageIfAvailable<R>(
-    _ body: (UnsafeBufferPointer<SystemChar>) throws -> R
+  public func withContiguousStorageIfAvailable<R>(
+    _ body: (UnsafeBufferPointer<_SystemChar>) throws -> R
   ) rethrows -> R? {
     try nullTerminatedStorage.withContiguousStorageIfAvailable(body)
   }
 
-  internal mutating func withContiguousMutableStorageIfAvailable<R>(
-    _ body: (inout UnsafeMutableBufferPointer<SystemChar>) throws -> R
+  public mutating func withContiguousMutableStorageIfAvailable<R>(
+    _ body: (inout UnsafeMutableBufferPointer<_SystemChar>) throws -> R
   ) rethrows -> R? {
     defer { _invariantCheck() }
     return try nullTerminatedStorage.withContiguousMutableStorageIfAvailable(body)
   }
 }
 
-extension SystemString: Hashable, Codable {}
+extension _SystemString: Hashable, Codable {}
 
-extension SystemString {
+extension _SystemString {
   // TODO: Below include null terminator, is this desired?
 
   internal func withSystemChars<T>(
-    _ f: (UnsafeBufferPointer<SystemChar>) throws -> T
+    _ f: (UnsafeBufferPointer<_SystemChar>) throws -> T
   ) rethrows -> T {
     try withContiguousStorageIfAvailable(f)!
   }
@@ -172,7 +173,7 @@ extension SystemString {
     _ f: (UnsafeBufferPointer<CInterop.PlatformUnicodeEncoding.CodeUnit>) throws -> T
   ) rethrows -> T {
     try withSystemChars { chars in
-      let length = chars.count * MemoryLayout<SystemChar>.stride
+      let length = chars.count * MemoryLayout<_SystemChar>.stride
       let count = length / MemoryLayout<CInterop.PlatformUnicodeEncoding.CodeUnit>.stride
       return try chars.baseAddress!.withMemoryRebound(
         to: CInterop.PlatformUnicodeEncoding.CodeUnit.self,
@@ -184,7 +185,7 @@ extension SystemString {
   }
 }
 
-extension Slice where Base == SystemString {
+extension Slice where Base == _SystemString {
   internal func withCodeUnits<T>(
     _ f: (UnsafeBufferPointer<CInterop.PlatformUnicodeEncoding.CodeUnit>) throws -> T
   ) rethrows -> T {
@@ -201,19 +202,19 @@ extension Slice where Base == SystemString {
     _ f: (UnsafePointer<CInterop.PlatformChar>) throws -> T
   ) rethrows -> T {
     // FIXME: avoid allocation if we're at the end
-    return try SystemString(self).withPlatformString(f)
+    return try _SystemString(self).withPlatformString(f)
   }
 
 }
 
 extension String {
-  internal init(decoding str: SystemString) {
+  internal init(decoding str: _SystemString) {
     // TODO: Can avoid extra strlen
     self = str.withPlatformString {
       String(platformString: $0)
     }
   }
-  internal init?(validating str: SystemString) {
+  internal init?(validating str: _SystemString) {
     // TODO: Can avoid extra strlen
     guard let str = str.withPlatformString(String.init(validatingPlatformString:))
     else { return nil }
@@ -222,27 +223,27 @@ extension String {
   }
 }
 
-extension SystemString: ExpressibleByStringLiteral {
-  internal init(stringLiteral: String) {
+extension _SystemString: ExpressibleByStringLiteral {
+  public init(stringLiteral: String) {
     self.init(stringLiteral)
   }
 
   internal init(_ string: String) {
     // TODO: can avoid extra strlen
     self = string.withPlatformString {
-      SystemString(platformString: $0)
+     _SystemString(platformString: $0)
     }
   }
 }
 
-extension SystemString: CustomStringConvertible, CustomDebugStringConvertible {
+extension _SystemString: CustomStringConvertible, CustomDebugStringConvertible {
   internal var string: String { String(decoding: self) }
 
-  internal var description: String { string }
-  internal var debugDescription: String { description.debugDescription }
+  public var description: String { string }
+  public var debugDescription: String { description.debugDescription }
 }
 
-extension SystemString {
+extension _SystemString {
   /// Creates a system string by copying bytes from a null-terminated platform string.
   ///
   /// - Parameter platformString: A pointer to a null-terminated platform string.
@@ -250,8 +251,8 @@ extension SystemString {
     let count = 1 + system_platform_strlen(platformString)
 
     // TODO: Is this the right way?
-    let chars: Array<SystemChar> = platformString.withMemoryRebound(
-      to: SystemChar.self, capacity: count
+    let chars: Array<_SystemChar> = platformString.withMemoryRebound(
+      to: _SystemChar.self, capacity: count
     ) {
       let bufPtr = UnsafeBufferPointer(start: $0, count: count)
       return Array(bufPtr)
@@ -276,7 +277,7 @@ extension SystemString {
     _ f: (UnsafePointer<CInterop.PlatformChar>) throws -> T
   ) rethrows -> T {
     try withSystemChars { chars in
-      let length = chars.count * MemoryLayout<SystemChar>.stride
+      let length = chars.count * MemoryLayout<_SystemChar>.stride
       return try chars.baseAddress!.withMemoryRebound(
         to: CInterop.PlatformChar.self,
         capacity: length / MemoryLayout<CInterop.PlatformChar>.stride
@@ -289,10 +290,10 @@ extension SystemString {
 }
 
 #if compiler(>=5.5) && canImport(_Concurrency)
-extension SystemChar: Sendable {}
-extension SystemString: Sendable {}
+extension _SystemChar: Sendable {}
+extension _SystemString: Sendable {}
 #endif
 
-// TODO: SystemString should use a COW-interchangable storage form rather
+// TODO: _SystemString should use a COW-interchangable storage form rather
 // than array, so you could "borrow" the storage from a non-bridged String
 // or Data or whatever
diff --git a/Tests/SystemTests/FilePathTests/FilePathExtras.swift b/Tests/SystemTests/FilePathTests/FilePathExtras.swift
index 82f11373..2402ea0d 100644
--- a/Tests/SystemTests/FilePathTests/FilePathExtras.swift
+++ b/Tests/SystemTests/FilePathTests/FilePathExtras.swift
@@ -8,7 +8,7 @@
 // Why can't I write this extension on `FilePath.ComponentView.SubSequence`?
 @available(/*System 0.0.2: macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0*/iOS 8, *)
 extension Slice where Base == FilePath.ComponentView {
-  internal var _storageSlice: SystemString.SubSequence {
+  internal var _storageSlice: _SystemString.SubSequence {
     base._path._storage[self.startIndex._storage ..< self.endIndex._storage]
   }
 }
@@ -39,7 +39,7 @@ extension FilePath {
 
     let (tail, baseTail) = _dropCommonPrefix(components, base.components)
 
-    var prefix = SystemString()
+    var prefix = _SystemString()
     for _ in 0..<baseTail.count {
       prefix.append(.dot)
       prefix.append(.dot)
diff --git a/Tests/SystemTests/SystemCharTest.swift b/Tests/SystemTests/SystemCharTest.swift
index 0ec5411e..9115e2ee 100644
--- a/Tests/SystemTests/SystemCharTest.swift
+++ b/Tests/SystemTests/SystemCharTest.swift
@@ -17,7 +17,7 @@ import XCTest
 
 final class SystemCharTest: XCTestCase {
   func testIsLetter() {
-    let valid = SystemString(
+    let valid = _SystemString(
       "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
     for char in valid {
       XCTAssertTrue(char.isLetter)
@@ -25,12 +25,12 @@ final class SystemCharTest: XCTestCase {
 
     // non printable
     for value in 0..<(UInt8(ascii: " ")) {
-      XCTAssertFalse(SystemChar(codeUnit: CInterop.PlatformUnicodeEncoding.CodeUnit(value)).isLetter)
+      XCTAssertFalse(_SystemChar(codeUnit: CInterop.PlatformUnicodeEncoding.CodeUnit(value)).isLetter)
     }
-    XCTAssertFalse(SystemChar(codeUnit: 0x7F).isLetter) // DEL
+    XCTAssertFalse(_SystemChar(codeUnit: 0x7F).isLetter) // DEL
 
     // misc other
-    let invalid = SystemString(
+    let invalid = _SystemString(
       ##" !"#$%&'()*+,-./0123456789:;<=>?@[\]^_`{|}~"##)
     for char in invalid {
       XCTAssertFalse(char.isLetter)
diff --git a/Tests/SystemTests/SystemStringTests.swift b/Tests/SystemTests/SystemStringTests.swift
index a1891714..9a256eaa 100644
--- a/Tests/SystemTests/SystemStringTests.swift
+++ b/Tests/SystemTests/SystemStringTests.swift
@@ -74,13 +74,13 @@ struct StringTest: TestCase {
     }
 
     // Test String, SystemString, FilePath construction
-    let sysStr = SystemString(string)
+    let sysStr = _SystemString(string)
     expectEqualSequence(string.unicodeScalars, sysStr.string.unicodeScalars)
     expectEqual(string, String(decoding: sysStr))
     expectEqual(string, String(validating: sysStr))
 
     let sysRaw = raw.withUnsafeBufferPointer {
-      SystemString(platformString: $0.baseAddress!)
+      _SystemString(platformString: $0.baseAddress!)
     }
     expectEqual(string, String(decoding: sysRaw))
     expectEqual(isValid, nil != String(validating: sysRaw))
@@ -99,8 +99,8 @@ struct StringTest: TestCase {
       "String(validatingPlatformString:)")
 
     // Test null insertion
-    let rawChars = raw.lazy.map { SystemChar($0) }
-    expectEqual(sysRaw, SystemString(rawChars.dropLast()))
+    let rawChars = raw.lazy.map { _SystemChar($0) }
+    expectEqual(sysRaw, _SystemString(rawChars.dropLast()))
     sysRaw.withSystemChars {  // TODO: assuming we want null in withSysChars
       expectEqualSequence(rawChars, $0, "rawChars")
     }
@@ -244,8 +244,8 @@ final class SystemStringTest: XCTestCase {
   // TODO: More exhaustive RAC+RRC SystemString tests
 
   func testAdHoc() {
-    var str: SystemString = "abc"
-    str.append(SystemChar(ascii: "d"))
+    var str: _SystemString = "abc"
+    str.append(_SystemChar(ascii: "d"))
     XCTAssert(str == "abcd")
     XCTAssert(str.count == 4)
     XCTAssert(str.count == str.length)