A set of state based CRDTs implemented in Erlang and on the paper - [A Comprehensive study of Convergent and Commutative Replicated Data Types] (http://hal.inria.fr/docs/00/55/55/88/PDF/techreport.pdf) - which you may find an interesting read.
Riak is getting CRDT support built in, so we've archived the old
riak_dt in the branch prototype. No further work will be done on
it. This repo is now a resuable library of Quickcheck tested
implementations of CRDTs.