I should point out Hurricane (http://gethurricane.org)

PHP: https://github.com/hurricane/driver-php

Python: https://github.com/hurricane/driver-python

Ruby: https://github.com/hurricane/driver-ruby

Java: https://github.com/hurricane/driver-java

All of the drivers fully re-implement the Erlang format, even the arcane parts (you can send Erlang closures around, for example).

Also -

C/C++: http://erlang.org/doc/man/ei.html

Ruby: https://github.com/mojombo/erlectricity

Java: https://github.com/fredlund/JavaErlang/

Seems nice. Last commit was almost a year ago though.

This is the sort of library that, once done, shouldn't need touching again. If it's already Python 3 compatible it may not need touching again for many years. (Assuming it's done. I have no direct experience.)

For Twisted: https://launchpad.net/twotp/

Twotp worked well for me after applying the fix in this bug report:

https://bugs.launchpad.net/twotp/+bug/767842