Comment by jackhiggs

What you're talking about there is a Model Repository. We're building one at the bank I work at, except because our modelling language (or meta model) is based on OMG's MOF we can generate artifacts (code) from our models. You can't do that with TLA+ as far as I know. It's pretty powerful - you can compose models together very easily, as well as generate loads of useful things for data-in-motion.