The reason it became de-facto was it had bindings to C/C++/Java (what most commercial software was written in from the 90s onwards) and worked on all main platforms (including most Unixes). There wasn't much else which provided that in the 90s, early 2000s.

RLM is a slightly more modern alternative to FlexLM which some software has moved to over the past 10 years from FlexLM.

Thanks, interesting to see that this seems like a niche market thats relitively untapped. What seems initially strange is its protecting SW that can be as much as 100k per seat (e.g. ASIC EDA licenses) I'm sure less scrupulous operations are pirating the SW, though perhaps the EDA vendors know the compabies who do pay are honest lest they are found out so a truly secure licensing system is less critical to them.

With most software in that price category, the actual software is a small piece of what you’re paying for. It’s really support, custom features, etc.

Additionally, the potential users that can pay have much bigger legal exposure using the pirated version and just wouldn’t risk it.

I've heard that pretty much the whole Chinese fabless scene runs on cracked EDA tools FWIW.

For sure, there is no legal risk for them.