I like the gratis tag. It is concise and has a fun ring to it.
On the other hand, I wonder if free-of-cost would be more clear and specific.
I've noticed that many posters forget to add the appropriate tag when looking for free-of-cost software.
Which verbiage do others prefer?
Oh, and please no free-as-in-beer. That one never makes sense, but many people like to use it, I think because they buy into the hyper-repetitive marketing that beer is somehow 'cool'.