[ec2m] Physics engines

[Martin C. Martin]

By the way, Critical Mass Labs have just announced new academic pricing
for Vortex, their branch of MathEngine.  You can now get an individual
license for $500.  It's a perpetual license for that major release, i.e.
you can use that major release and all point upgrades and maintenace
patches forever.  It also includes some demo time, i.e. you can run it
without connecting to the license server, so you can run it at
conferences on your laptop, etc.

- Martin