You say that "With the help of this library it is possible to build Erlang-Style mailboxes", but how would you solve the issue of static typing?
this wasn't an issue for me because I wanted as much type checking as possible. In many implementations, you have an implicit contract between the sender and the receiver process. In this case, the contract is explicit and the compiler can tell me if I'm trying to send or receive "wrong" data.
Besides, Holumbus depends on package 'unix', preventing it from being used on non-unix platforms.
Oh... hmm, I think, the unix-package is only needed for the console-modules. The distribution modules should not need them, but I may be wrong. I don't have access to proprietary plattforms, but I think about splitting the distribution package and extract the communication modules.