Before installing and probably messing up my other installation, I'd like to ask if the SQL Anywhere 12 Web edition can be run in parallel to a workgroup edition (for example) on the same machine, i. e. does it have another daemon process or does it also run dbsrv12 process? I am wondering if I understand correctly that this edition is really free for production use, if only Browser based access is used?
AFAIK, the Web Edition uses the same binaries as the other editions.
Note, when run on Windows, installing two versions of the same major version is not supported, as documented in this FAQ - cf. José's official answer.
Addition: From Mark's comment there, one could conclude that for Mac OS X (as a Unix derivate), parallel installs of the same major version should work. But like Breck, "I'm just guessing":)