No discussion of Ada is complete without referencing the cost of commercial development licenses. They're expensive. Very expensive.

Any enthusiasm for this language is inevitably quashed upon encountering the $$,$$$ per-seat price of the compilers for the absolute bare-bones x86 version. It's more if you want to target non x86. I pester AdaCore for info every few years and while they've dropped a little bit, they're still out of reach for companies not in the Fortune 500. I'd love to use SPARK, but I don't see that happening any time soon.