diff --git a/lib/rdoc.rb b/lib/rdoc.rb
index 8c3559c241..84fe8e1f1e 100644
--- a/lib/rdoc.rb
+++ b/lib/rdoc.rb
@@ -167,6 +167,7 @@ def self.home
   autoload :Store,          "#{__dir__}/rdoc/store"
   autoload :Task,           "#{__dir__}/rdoc/task"
   autoload :Text,           "#{__dir__}/rdoc/text"
+  autoload :Server,         "#{__dir__}/rdoc/server"
 
   autoload :Markdown,       "#{__dir__}/rdoc/markdown"
   autoload :Markup,         "#{__dir__}/rdoc/markup"
diff --git a/lib/rdoc/generator/darkfish.rb b/lib/rdoc/generator/darkfish.rb
index 96bb4fb66f..2321b37041 100644
--- a/lib/rdoc/generator/darkfish.rb
+++ b/lib/rdoc/generator/darkfish.rb
@@ -238,7 +238,7 @@ def write_style_sheet
   # Build the initial indices and output objects based on an array of TopLevel
   # objects containing the extracted information.
 
-  def generate
+  def generate(server_mode: false)
     setup
 
     write_style_sheet
@@ -246,11 +246,13 @@ def generate
     generate_class_files
     generate_file_files
     generate_table_of_contents
-    @json_index.generate
-    @json_index.generate_gzipped
-
-    copy_static
 
+    unless server_mode
+      # For the server, we only generate the JSON index if requested
+      @json_index.generate
+      @json_index.generate_gzipped
+      copy_static
+    end
   rescue => e
     debug_msg "%s: %s\n  %s" % [
       e.class.name, e.message, e.backtrace.join("\n  ")
diff --git a/lib/rdoc/options.rb b/lib/rdoc/options.rb
index 2631d57364..fb31405227 100644
--- a/lib/rdoc/options.rb
+++ b/lib/rdoc/options.rb
@@ -340,6 +340,11 @@ class RDoc::Options
 
   attr_reader :visibility
 
+  ##
+  # The server's port to listen on. `nil` means the server is disabled.
+
+  attr_reader :server_port
+
   ##
   # Indicates if files of test suites should be skipped
   attr_accessor :skip_tests
@@ -392,6 +397,7 @@ def init_ivars # :nodoc:
     @encoding = Encoding::UTF_8
     @charset = @encoding.name
     @skip_tests = true
+    @server_port = false
   end
 
   def init_with map # :nodoc:
@@ -1116,6 +1122,15 @@ def parse argv
 
       opt.separator nil
 
+      opt.on(
+        "--server[=PORT]",
+        Integer,
+        "[Experimental] Run WEBrick server with generated documentation.",
+        "Uses port 4000 by default. Will use ./tmp for file output."
+      ) do |port|
+        @server_port = port || 4000
+      end
+
       opt.on("--help", "-h", "Display this help") do
         RDoc::RDoc::GENERATORS.each_key do |generator|
           setup_generator generator
diff --git a/lib/rdoc/rdoc.rb b/lib/rdoc/rdoc.rb
index 47108ceee3..7b8d278dda 100644
--- a/lib/rdoc/rdoc.rb
+++ b/lib/rdoc/rdoc.rb
@@ -463,7 +463,7 @@ def document options
       exit
     end
 
-    unless @options.coverage_report then
+    unless @options.coverage_report || @options.server_port
       @last_modified = setup_output_dir @options.op_dir, @options.force_update
     end
 
@@ -496,9 +496,16 @@ def document options
 
       @generator = gen_klass.new @store, @options
 
-      generate
+      if @options.server_port
+        start_server
+      else
+        generate
+      end
     end
 
+    # Don't need to run stats for server mode
+    return if @options.server_port
+
     if @stats and (@options.coverage_report or not @options.quiet) then
       puts
       puts @stats.summary.accept RDoc::Markup::ToRdoc.new
@@ -507,6 +514,26 @@ def document options
     exit @stats.fully_documented? if @options.coverage_report
   end
 
+  def start_server
+    begin
+      require 'webrick'
+    rescue LoadError
+      abort "webrick is not found. You may need to `gem install webrick` to install webrick."
+    end
+
+    # Change the output directory to tmp so it doesn't overwrite the current documentation
+    Dir.chdir "tmp" do
+      server = WEBrick::HTTPServer.new Port: @options.server_port
+
+      server.mount '/', RDoc::Server, self
+
+      trap 'INT'  do server.shutdown end
+      trap 'TERM' do server.shutdown end
+
+      server.start
+    end
+  end
+
   ##
   # Generates documentation for +file_info+ (from #parse_files) into the
   # output dir using the generator selected
diff --git a/lib/rdoc/server.rb b/lib/rdoc/server.rb
new file mode 100644
index 0000000000..dfe23346f8
--- /dev/null
+++ b/lib/rdoc/server.rb
@@ -0,0 +1,175 @@
+# frozen_string_literal: true
+require 'erb'
+require 'time'
+require 'json'
+
+class RDoc::Server < WEBrick::HTTPServlet::AbstractServlet
+  ##
+  # Creates an instance of this servlet that shares cached data between
+  # requests.
+
+  def self.get_instance server, rdoc # :nodoc:
+    new server, rdoc
+  end
+
+  ##
+  # Creates a new WEBrick servlet.
+  #
+  # +server+ is provided automatically by WEBrick when mounting.
+  # +rdoc+ is the RDoc::RDoc instance to display documentation from.
+
+  def initialize server, rdoc
+    super server
+
+    @rdoc = rdoc
+    @generator = rdoc.generator
+    @generator.file_output = false
+
+    darkfish_dir = File.join(__dir__, 'generator/template/darkfish/')
+    json_index_dir = File.join(__dir__, 'generator/template/json_index/')
+
+    @asset_dirs = {
+      :darkfish   => darkfish_dir,
+      :json_index => json_index_dir,
+    }
+  end
+
+  ##
+  # GET request entry point.  Fills in +res+ for the path, etc. in +req+.
+
+  def do_GET req, res
+    req.path.sub!(/\A\//, '')
+
+    case req.path
+    when '/'
+      res.body = @generator.generate_servlet_root installed_docs
+      res.content_type = 'text/html'
+    when 'js/darkfish.js', 'js/jquery.js', 'js/search.js', %r{^css/}, %r{^images/}, %r{^fonts/}
+      asset :darkfish, req, res
+    when 'js/navigation.js', 'js/searcher.js'
+      asset :json_index, req, res
+    when 'js/search_index.js'
+      res.body = "var search_data = #{JSON.dump @generator.json_index.build_index}"
+      res.content_type = 'application/javascript'
+    else
+      show_documentation req, res
+    end
+  rescue WEBrick::HTTPStatus::NotFound => e
+    not_found @generator, req, res, e.message
+  rescue WEBrick::HTTPStatus::Status
+    raise
+  rescue => e
+    $stderr.puts e.full_message
+    error e, req, res
+  end
+
+  private
+
+  def asset generator_name, req, res
+    asset_dir = @asset_dirs[generator_name]
+
+    asset_path = File.join asset_dir, req.path
+
+    res.body = File.read asset_path
+
+    res.content_type = case req.path
+                       when /\.css\z/ then 'text/css'
+                       when /\.js\z/  then 'application/javascript'
+                       else                'application/octet-stream'
+                       end
+  end
+
+  def error exception, req, res
+    backtrace = exception.backtrace.join "\n"
+
+    res.content_type = 'text/html'
+    res.status = 500
+    res.body = <<-BODY
+<!DOCTYPE html>
+<html>
+<head>
+<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
+
+<title>Error - #{ERB::Util.html_escape exception.class}</title>
+
+<link type="text/css" media="screen" href="/css/rdoc.css" rel="stylesheet">
+</head>
+<body>
+<h1>Error</h1>
+
+<p>While processing <code>#{ERB::Util.html_escape req.request_uri}</code> the
+RDoc (#{ERB::Util.html_escape RDoc::VERSION}) server has encountered a
+<code>#{ERB::Util.html_escape exception.class}</code>
+exception:
+
+<pre>#{ERB::Util.html_escape exception.message}</pre>
+
+<p>Please report this to the
+<a href="https://github.com/ruby/rdoc/issues">RDoc issues tracker</a>.  Please
+include the RDoc version, the URI above and exception class, message and
+backtrace.  If you're viewing a gem's documentation, include the gem name and
+version.  If you're viewing Ruby's documentation, include the version of ruby.
+
+<p>Backtrace:
+
+<pre>#{ERB::Util.html_escape backtrace}</pre>
+
+</body>
+</html>
+    BODY
+  end
+
+  def not_found generator, req, res, message = nil
+    message ||= "The page <kbd>#{ERB::Util.h req.path}</kbd> was not found"
+    res.body = generator.generate_servlet_not_found message
+    res.status = 404
+  end
+
+  PAGE_NAME_SUB_REGEXP = /_([^_]*)\z/
+
+  def show_documentation req, res
+    store = @rdoc.store
+    # Clear all the previous data
+    store.classes_hash.clear
+    store.modules_hash.clear
+    store.files_hash.clear
+
+    # RDoc instance use last_modified list to avoid reparsing files
+    # We need to clear it to force reparsing
+    @rdoc.last_modified.clear
+
+    # Reparse the files
+    @rdoc.parse_files(@rdoc.options.files)
+
+    # Regenerate the documentation and asserts
+    @generator.generate(server_mode: true)
+
+    case req.path
+    when nil, '', 'index.html'
+      res.body = @generator.generate_index
+    when 'table_of_contents.html'
+      res.body = @generator.generate_table_of_contents
+    else
+      text_name = req.path.chomp '.html'
+      name = text_name.gsub '/', '::'
+
+      content = if klass = store.find_class_or_module(name)
+        @generator.generate_class klass
+      elsif page = store.find_text_page(name.sub(PAGE_NAME_SUB_REGEXP, '.\1'))
+        @generator.generate_page page
+      elsif page = store.find_text_page(text_name.sub(PAGE_NAME_SUB_REGEXP, '.\1'))
+        @generator.generate_page page
+      elsif page = store.find_file_named(text_name.sub(PAGE_NAME_SUB_REGEXP, '.\1'))
+        @generator.generate_page page
+      end
+
+      if content
+        res.body = content
+      else
+        not_found @generator, req, res
+      end
+    end
+  ensure
+    res.content_type ||= 'text/html'
+  end
+end
diff --git a/rdoc.gemspec b/rdoc.gemspec
index 0730f77a22..442d8e70c9 100644
--- a/rdoc.gemspec
+++ b/rdoc.gemspec
@@ -210,6 +210,7 @@ RDoc includes the +rdoc+ and +ri+ tools for generating and displaying documentat
     "lib/rdoc/ri/task.rb",
     "lib/rdoc/ri/servlet.rb",
     "lib/rdoc/rubygems_hook.rb",
+    "lib/rdoc/server.rb",
     "lib/rdoc/single_class.rb",
     "lib/rdoc/stats.rb",
     "lib/rdoc/stats/normal.rb",
diff --git a/test/rdoc/test_rdoc_options.rb b/test/rdoc/test_rdoc_options.rb
index 5e8b1ae3d8..fafc9d4074 100644
--- a/test/rdoc/test_rdoc_options.rb
+++ b/test/rdoc/test_rdoc_options.rb
@@ -82,6 +82,7 @@ def test_to_yaml
       'title'                => nil,
       'visibility'           => :protected,
       'webcvs'               => nil,
+      'server'               => false,
       'skip_tests'           => true,
     }