The source code of the WebMinster WebPlayer is available under the GNU Lesser General Public License (LGPL). The SVN server, bug tracker and other cool development stuff is hosted by SourceForge. The developer name of the WebMinster WebPlayer is Vanadium.
If you want to add a new or improve a feature you should install the needed software. You can use Windows or any other OS instead of Ubuntu of course. Then you must check out the latest source codes from our SVN server (this can be done with the subclipse plugin for the eclipse IDE).
After this you can try to compile the source code. We have made a make file for this task. Then leave a message in our forum or on our mailing list if you were able to compile the source code and tell us which feature you want to change or to add. We will then point you to the code classes which must be changed to implement this feature. But you should read the whole coding guides first to get a good overview over the source code and over the directory structure.