It takes longer for commercial codebases to be ported, pass all the stages of productization, and be officially launched. My prediction is for a few such projects to show up later this year.
With that said, there are some uses of emscripten that are not demos. For example emscripten was used to port the crunch decoder to JS in gl-matrix, and that might well be used in non-demos. Also there are educational sites using compiled languages like repl.it as another commenter mentioned. I've also seen a few other practical uses, e.g. of sql.js in sqlfiddle.
I know you Mozilla guys don't have time to maintain ports, but are you doing anything to encourage open source devs to actually use and maintain this stuff? I'm working on an emscripten port of a game myself that I do want to actually maintain and improve upon, but I get the impression that I am in the minority.
I used to have time to maintain at least sql.js, ammo.js and box2d.js, but recently work on asm.js and some porting projects has monopolized my efforts I'm afraid. My hope is people that use it will maintain those.
> but are you doing anything to encourage open source devs to actually use and maintain this stuff?
Do you mean ports like sql.js and ammo.js that I began, or new ports people make?
I don't know how to encourage people to work on my ports - either they do or they don't ;) I ask for help and mention the projects, but it's up to people to be interested of course.
Regarding other people's ports, I definitely try to support them as much as possible. Fixing bugs that those ports encounter is always high priority for me.
> I'm working on an emscripten port of a game myself that I do want to actually maintain and improve upon, but I get the impression that I am in the minority.
There are a few serious/long-running ports, like jsmess and nebula3. But most ports are more short-term: they accomplish the goal, and then not much is left to do.
There are also commercial emscripten ports, but most commercial work by nature is secret until it launches.