Open Source
Imagine those Itanium users when MS decided not to support iTanic in future Windows versions ... they were f*d, ok, bad example, they were already when they chose iTanic ... but still.
Here, MongoDb says they will not support Solaris for new versions, anymore ... fine, guess what, if you want to use MongoDb on Solaris, you can hire a dev or two and fork that.
With proprietary software you are f'd, with Open Source you can always fork it.
