Hydrogen is an advanced drum machine created by Alessandro Cominu, an Italian programmer who goes by the pseudonym Comix. Its main goal is to provide professional yet simple and intuitive pattern-based drum programming.
Hydrogen was originally developed for Linux, but later ported to Mac OS X. Support for Microsoft Windows seemed to have been abandoned, since the last build dated to 2006 for 4 years, but a Microsoft Windows port exists as a snapshot of the upcoming 0.9.6 version, indicating that Microsoft Windows is likely to be supported in the future.