Q:

IPC mono <-> .NET?

I have two processes running on the same windows machine. One is using mono, the other is using MS .NET.
What is the best solution for inter process communication?

A:

Really, I would say you need to provide more information for a good answer.  The type of IPC depends on your needs.  I've used several types of IPC, shared memory, files, memory mapped files, pipes, sockets, etc.  I think this question is less about .Net vs. Mono and more about you specific needs.
That said, I've used mostly TCP and UDP for most of my applications.  The VM, language, computer, etc. become irrelevant when you put your communications over the network.  For local communications your loopback device (127.0.0.1) works great.  If you ever decide to take your application to another machine, you only need to change addresses.
Put your data (e.g. http in an existing protocol and you'll get out-of-the-box from most languages...

