Unfortunately, the offline editor requires Adobe Air, so Linux users have to install unsupported and outdated software in order to use it. The current version of Air is 3.9, but version 2.6 is the last version available for Linux.
Scratch is still very nice, but the Flash & Air requirements are really an unfortunate step backwards in openness.
Salsa looks brilliant. Really looking forward to playing around with it.
But shouldn't the link to github in the article point to https://github.com/idbygeorge/salsa instead of https://github.com/dhcolumbia/opensyllabus ?