Forban is a P2P file sharing application for link-local and local area networks. Forban works independently from the Internet and uses only the local area capabilities to announce, discover, search, or share files. Forban relies on HTTP and is opportunistic, meaning that it replicates any files of interest seen in its proximity. The Forban protocols are minimalistic to ease the production of other implementations.
Gtk-Gnutella is a full-featured Gnutella client using GTK+. It contains all widely deployed Gnutella features, including DHT support. It is extremely efficient, using little CPU time and memory. It is meant to be left running 24x7. It is fully compatible with UPnP and NAT-PMP, and as such is easy to use behind a firewall supporting one of these port mapping technologies.