Hydrogen is an advanced drum machine for GNU/Linux, Windows and Mac OS X. It's main goal is to bring professional yet simple and intuitive pattern-based drum programming.
This is a REALLY GOOD software with all the basic functions. I wish it had more functionality though. I am gonna use it mainly for my BeatBuddy guitar pedal drum machine thingy- mybeatbuddy.com it should actually go well with this program I think. I really need something simple like this program. I highly recommend it!! Not as advanced as the more advanced programs though, but still REALLY GOOD!!!