Welcome to the EFM website!
EFM aims to be a better alternative to RTF for writing and editing fiction. It is a plain text based format, which means there are many, many tools that can edit it - even Notepad will handle it, if you make sure to pick "UTF-8" when you save it.
Currently, the only tool for EFM is one to convert it to RTF. Hopefully, this will be useful for anyone who wants to write fiction in a program that doesn't save RTF (or on something like an Alphasmart). You can read all about EFM's already-existing features here.
If you want to use EFM, here's how to get it and run it.
Go here to join the mailing list or read its archives.
Once the converter-to-RTF has most of the planned features and is polished up a bit, then I will work on a tool or tools for tracking changes when editing.