This is a list of general, non-driver specific things, that need improvement in MESS. If you want to contribute but don't know what to do, this list can give you some pointers.

• Clean up old drivers. There are still lots of drivers without an active maintainer and as such, they are sometimes in a very bad shape. Converting them to current coding conventions and adding comments would be very useful.
• Improve skeleton drivers. In MESS, there are many drivers in a very preliminary state. These are usually added to the source to document the available BIOS dumps and to provide a basic description of the hardware. Adding more functionalities, with the final goal of proper emulation, would be very appreciated.
• Implement mizapf's XML format to store ROM infos in more drivers, to help MESS loads cartridges with multiple ROMs. Currently, we use a zip file containing the ROMs and a layout.xml file to describe them (where to load, how to handle them, etc.). However, some systems may need subtle modifications to make use of this system.