Possibly, you have heard of the eDonkey filesharing program. Since long, there exists a compatible OpenSource-Program called MLDonkey. MLDonkey needs a Unix based system to run (although I think, i’ve heard of a cygwin port). MLDonkey has a nice GUI and generally seems to work better than the original Linux-Client – even more in combination with the Windows-Remote-Control-GUI MLDonkey Watch.
The developer of MLDonkey seems to not longer have time to continue the development, which is a shame as there are still some small problems with the client – some of them making problems on the eDonkey-Servers out there.
Pierre Etchemaite now provides some patches under http://concept.free.free.fr/mldonkey which fix a lot of the problems currently still in the client. If you want to use MLDonkey, you should really apply them.
On the Mailinglist (subscription via the Savannah-Page linked above) the patches and their results are discussed.
Don’t hesitate and give MLDonkey and the Pango-Patches a try!