This was put together to give a simple .NET client wrapper around the KillBill HTTP API (http://killbill.io/api)
However the main objective was mostly for me to learn the HTTP API... this client is incomplete and a blatant and poor rip off of the KillBill Java Client.
We have been using it in a production platform for very simple direct payments for a couple of years... but are now ready to expand into subscriptions / billing / catalog and as such this client will eventually be updated to cover our use cases.
I doubt we have the time to achieve full API coverage... and furthermore this client was put together without the .NET 4.5 HTTP ASYNC ... that is almost a deal breaker immediately.
If you want to FORK and butcher it for your own needs... please do so.