I don't know about techno specifically (not my cup of tea - I thought techno composers just used Atari STs and four track sequencers - Har har).
Seriously though, if you're looking for some sort of sequencer, maybe take a look at LMMS. If you want to do serious multi-track stuff maybe have a look at Ardour (it's complex though). There's also a nice drum machine called Hydrogen.
Probably not what you want, but maybe also consider having a look at rosegarden.
Last edited by matthewg42; 10-02-2007 at 05:58 PM.