Clojure has a lot to recommend itself but you'd want to avoid JVM based languages for resource contraint reasons.

Haskell  has a lot going for it but you'd want to avoid compiled languages for portability reasons when dealing with heterogenous p2p systems.

Agda, Idris, Coq et all have a lot going for them too but they're too complex for common use.

That doesn't leave many choices.