The link on the comparison page is a little muted, so I didn't notice it right away.

In case anyone is curious about strong-pm vs. pm2 vs. forever: http://strong-pm.io/compare/

This is a more full featured than forever. Check out the comparison chart.

Is this open source?

The site doesn't actually say what the license is, only that it's "open source". The repo lists it as dual licensed, under Artistic 2.0 or the commercial StrongLoop license.