drumbit - A very easy to use drum machine.
Sampulator - Make (and record) beats on your keyboard
Remixlive - Remixer, beat maker and finger drumming instrument for iOS.
Onemotion Drum Machine - Drum Machine is a fully-featured web-based app developed by OneMotion to enable you to create Drum Beats and patterns.
Splice Beat Maker - Make and share beats in your browser
Type Drummer - Drum by typing