Authlib has come a long way since it's first release in November 2000. SourceForge counts it's downloads to over 30000 and our statistics claim over 75000 (Authlib was available for download directly from devhome.net)
It's been a fairly lengthy period of time since a release was made public, and frankly, development had pretty much halted, until very recently.
Major milestones have been achieved in developing the templating and form validation arenas, and so Authlib's next version is expected quite soon.
RC4.NET has been released under the Lesser GNU GPL. It is written in C# however it looks and performs (programmatically) very much like the RC4Crypt libary for PHP.
This is an initial effort to provide an implementation of the RC4 encryption algorithm for the .NET environment. This is not to say that other implementations donot exist.
RC4Crypt was updated last evening on SourceForge and is immediately available for download. I believe there was some formatting issues, those have been addressed.
This release marks mature stability for the library. A C# version of this library will also be released soon.