I recently wrote about compiling Mosh for OI, and ended by saying I couldn't get it working. Thanks to the help from the list post I mentioned, I got it compiled, and was able to execute the binary. However, it didn't work. Connecting to it failed always, and the compiled client just output the word "hangup" and then exited.
I gave up at this point, and have since installed a guest Ubuntu VM, and installed Mosh on that, then from that mosh session, SSH'd to the OI box. It's not pretty, but it works.