Hi,
Can we send, and receive, SysEx ? If so, how to ?
I want to build an editor for the Elektron Machinedrum 
Nope, we can’t. This has been requested many times. The only way is to use Sysex is via something like Midiyoke + Miditranslator 
We can:
See https://code.google.com/p/xrnx/source/browse/trunk/Snippets/Midi.lua for some examples.
See http://code.google.com/p/xrnx/source/browse/trunk#trunk/Documentation -> Renoise.Midi.API.lua for the API reference.
Let us know if you need more info please.
is anyone planning to write a tool to build on this?
Woah thank you 
I will try this tonight, I’ll let you know if I got issues
Does it work?? Any news on this??
I’m interessted in a sysex-plugin, too.
Me too!!