# What implementations are available, how do they compare?

All implementations are based on DEC SRC Modula-3. Critical Mass offers an improved version with commercial support. It features incremental garbage collection on NT, and a few additional packages like ODBC database access. Ecole Polytechnique de Montréal has an updated distribution. It features integrated documentation, weekly updates, pre-compiled binaries for several platforms, and debugging support on NT.

Special versions have been developed for OS/2 and DOS and are available on the Polymtl site.