Credence is a tool for combating spam and pollution in filesharing networks. It lets you vote on files in the network, analyzes the votes of your peers so that you can avoid polluted files, and automatically identifies the voters in the network that are most credible and useful. It is built as an extension to LimeWire, running on the Gnutella filesharing network.
xbmsd is a file sharing daemon that uses the Xbox Media Streaming Protocol (XBMSP) supported by the Xbox Media Center. It also supports the XBMSP Server Discovery Protocol (XBSDP). Its main features are mapping files to arbitrary local files or HTTP files/streams, support for filetype-specific, "synthetic" mplayer configuration files, and support for filtering files with arbitrary programs, which can, for example, re-encode media files on the fly.