It is available for multiple platforms, including Microsoft Windows and POSIX systems such as Linux For copyright reasons, the emulator cannot be distributed with original MSX-BIOS ROM images.

Instead, openMSX includes C-BIOS, a minimal implementation of the MSX BIOS, allowing some games to be played without the original ROM image.

Utilizing this communication protocol enables to write versatile add-ons for openMSX.

Projects making use of this protocol include the following applications: There is a dead subproject to redevelop Catapult, a GUI developed for the emulator that is part of the project, utilizing Python and the Qt toolkit.

So, as of release 20.0, a GUI was integrated that replaces almost all functionality of the Catapult and separate Debugger programs.