10beta Release

This is the latest release and marked as beta (see below). This is fine for casual users who want to sample MMT. Regular users probably want to wait for the proper release.

It migrates to Scala 2.12 and supports almost all of the recent language features used in the urtheories and examples repositories.

We're marking this as a beta release because we got a bit bogged down by FLoC deadlines last week and haven't had time yet to run the usual tests and fully merge the development branch into master.

This release is fine for casual users, who want to sample MMT.
Regular users may want to wait for the proper release.