does anyone know?

not really

but on the inside of the Devlab case it says that Devin used Cubase SX, Ableton Live and Wavelab Software to make Devlab if that's any help...

Yes he loves Ableton "It's awesomee, awesome!"

Ableton is a very nice program.
I use it myself. It's user-friendly and top quality.

I read somewhere that Devin uses Nuendo for his demo's as well...
But the rest is just one big mystery... does SYL use hardware when they play live, or is is someone on keys, triggering sounds/samples?

does SYL use hardware when they play live, or is is someone on keys, triggering sounds/samples?

Their keyboardist plays all synths + triggers the samples.