I've put up the first public version of my FM-Sid driver. Comes with docs and a couple of (currently windows tools) to convert XM files to the right format , and also Goat Tracker 2 if you want to use an external SID player with it.
FM-Sid is probably the first c64 music driver that lets you use the SFX FM Expander cartridge when composing, giving you 12 channels in total. It allows you to either write songs with the basic stand-alone driver, or use another editor to provide the SID channels while the driver plays back the FM ones. This means using tools with multi-SID support (such as Sid Wizard or Goat Tracker) can give you up to 18 channel songs on one C64. (9 SID channels + 9 FM channels)
As I'm going to be incredibly busy for the next few months I've decided to release the in development version of FM-Sid "as is", until I get time to work on the proper additions for v1.4.
note : If you don't like editing music with external tools and assemblers you won't enjoy using this, it is NOT a standalone tracker and never will be. 