Lots of software licenses have “non-compete” clauses that forbid you from using it to develop a competing product. Wouldn’t surprise me if there was a compiler or two out there with that restriction, most likely niche languages.
Oracle database has a clause forbidding anyone to publish benchmarks of it.
It's been common in electronic design automation tools to have license terms like that (forbidding use to create a competing product). However, competing companies have often found workarounds, either by finding loopholes or just breaking rules and hoping not to get caught.
balmer told us that gpl is cancer, but true cancer is us model of licensing
If a person were to receive data from someone subjected to such restriction, is the receiver bounded by the same restriction?
How the hell is non-compete legal in market economy? Competition is one of its core strengths. Why would anyone let anyone opt out of this, even a little bit?
Those clauses should be illegal.