Well, there are many reasons to use React (the large ecosystem means you can find libraries and tutorials easily, for example) but yes, the license is a deal breaker for many, especially larger companies with legal teams who actually understand the ramifications.

It depends on how many software patents the company owns. In most cases it's 0

It could also matter if you're in violation of a patent held by Facebook or any of its subsidiaries.

Microsoft has no problem using React -- what are the ramifications?

Microsoft, Netflix, and Twitter most likely have agreements in place with Facebook regarding the use license.

Source: I worked for a large company that had banned the use of React for all external facing projects, recently Facebook and their lawyers came to an agreement and now it's widely used.

Doesn't Netflix as well?

Yep, and Palantir also. I wish my company would be more open to using it, but the patent issue makes it a non-starter for us.

If you're MS, there are no ramifications.

They recently changed the RocksDB licence (https://github.com/facebook/rocksdb/commit/3c327ac)

This reopenned the discussion about React licensing (https://github.com/facebook/react/issues/10191) so maybe this will change soon.

Not sure what specifically your aversion is to the React license, but a similar project - Preact - uses an MIT license: https://github.com/developit/preact

NOTE: not affiliated with Preact (I live in the caves of the backend).

How does Preact not violate React's patent if it's a drop in library?

React isn't patented

My bad it's a "patent rider". I should know better.

When has the ridiculous license ever been an actual problem for anyone?

What is wrong with its license?

They're referring to the 'patent retaliation clause', see: https://medium.com/@dwalsh.sdlr/react-facebook-and-the-revok...

Logically following the conversation.... What's wrong with their patent retaliation clause?

The link you provided basically says it only matters if you are a patent troll.

Yeah I don't have a stake/opinion, just posted that particular article because it's a recent, thorough take, by a lawyer.

My understanding of this licence is "we're making open-source software, play by the rules and don't sue us or we might find other ways to put you in trouble"