I really like PortableApps and use a lot of the tools. One program (that I believe fits the required criteria?) that I thought would be nice (but I lack the expertise) is the WinTin++ Mud Client. I can't seem to find a license agreement on their webpage, but the source is available for download.
I believe this is an original request because I have searched the forums for wintin.
Link to website:
TinTin++ Mud Client
Description of Software:
A Mud Client that (at least for the Windows version) utilizes cygwin, putty and the TinTin++ code to provide mud client functionality for Windows users. (See the "How does WinTin++ work?" question in the WinTin++ FAQ).
Hope that I met all the criteria from the Un-official Request thread.