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. It is possible for the user to replace C-BIOS by native BIOS if they prefer.
OpenMSX emulates a large amount of MSX systems and MSX related hardware, including:
Reverse support (go back in emulated time to correct mistakes or debug what happened)
OpenMSX has an open communication protocol to communicate with the openMSX emulator. Utilizing this communication protocol enables to write versatile add-ons for openMSX. Projects making use of this protocol include the following applications:
openMSX Catapult (by the openMSX team)
openMSX Debugger (by the openMSX team)
openMSXControl plugin
NekoLauncher openMSX
openMSX Peashooter
openMSX Control Plugin for Gedit
Currently Catapult, a GUI developed for the emulator that is part of the project, is being redeveloped utilizing Python and the Qt toolkit.
The openMSX Debugger is also under development, written in C++, also utilizing the Qt Toolkit.
However, with release 20.0, a GUI was integrated that replaces almost all functionality of the Catapult and separate Debugger programs. Both these sub-projects will not be developed further, in favour of the built-in functionality.