Download from TomP2P-4.0.0-dist.zip and TomP2P-4.0.0-dist.tar.bz2 from the Maven repository.
Changelog for TomP2P 4.0.0
* Better UPNP support and new NAT-PMP (jNAT-PMPlib) support.
* New persistant connections, because the user knows best when a connection should stay open.
* New connection handling and connection reservation.
* Upgraded libraries (Netty, Guava, BerkleyDB).
* Lots of fixes.