[alangpierce]

It's also a bit strange in that Flow and TypeScript are competing JS language extensions with nearly the same goals and scope, yet TypeScript is seen as its own language and Flow isn't. And, of course, JSX isn't valid JavaScript, but React programmers view themselves as writing code in JS. IMO, it would be better to put TypeScript projects in the JavaScript category and optionally have more detailed stats on the different JavaScript variants.

When I introduced TypeScript to my team at work, one of the things that I had to emphasize was that TypeScript isn't a new language; it looks and behaves just like JS, it just has some new syntax to declare types.

I suppose the practical matter here is that GitHub language stats can distinguish TypeScript because it uses the .ts extension, while other JS variants just stick with .js (and JSX sometimes is .jsx, but not always).