TSplus as an alternative to RDS without paying RDS license fees to microsoft

I am aware of several established and relatively large German companies that use TSplus in production. These are not small organizations operating without governance; they are typically subject to internal controls, external audits, software asset management procedures, compliance reviews, and in some cases Microsoft licensing audits.

If TSplus inherently violates Microsoft licensing terms or operates illegally by design, it is difficult to understand how such deployments continue for years without being identified during those audits.

Of course, the fact that large companies use a product does not automatically prove that every deployment is correctly licensed. Audits may also differ in scope. However, this suggests that the matter may be more nuanced than simply stating that “TSplus is illegal.”