[tsomctl]

Note that the Z3 source code has been available for a while, but a commercial license was $10,000.

[wslh]

$ 10,000 seems like a magic number. Another Microsoft Research project, Detours [1] costs $ 9,999.95.

[1] http://www.microsoftstore.com/store/msus/en_AU/pdp/Microsoft...

[raverbashing]

Yes

It's cheap enough for a company to buy it without many signatures, but also on the upper scale of what people who "don't want Open Source" can pay.

[Drakim]

I wonder who bought the last license, and how long since it now became free to use.

[CHY872]

I suspect that they've sold a fair few licenses in their time. SMT solvers are widely used in industry, and to my knowledge Z3 is one of the better ones.

It's probably just that the volume of sales isn't going to make sense when comparing to the size of the team.