TomP2P is a distributed hash table with additional features, such as storing multiple values for a key.
Key/Value
http://tomp2p.net/
https://github.com/tomp2p/TomP2P
https://tomp2p.net/doc/
Thomas Bocek
CH
2004
Open Source
Java
MapDB
Apache v2
https://en.wikipedia.org/wiki/TomP2P