Souldfind is a free implementation of the SoulSeek server (currently supporting Nicotine, museek and pySoulSeek clients, also the official SoulSeek client with some tricks). It's written in the D programming language. Reproducible: Always
While the source code of the project can still be found on FreeCode, its last release dates back to May 2006 and the supposed project site at http://soulfind.seeschloss.org/ no longer exists.