Sublime is a zillion times faster than Atom, and brackets isn't something that enters into the same league as either. I don't see how open-sourcing will help it.
Just a few days ago I got an email from a plugin developer (Sublimall), anounching that they're stopping development. Quote from the email: "There is no community, no documentation, API is not well designed and there is absolutely no communication with Sublime Text developers.".
I don't know if I can recommend it, really. There's a real risk other plugins I rely on won't be maintained anymore.
>Just a few days ago I got an email from a plugin developer (Sublimall)
Well, that's just one developer though -- and who might be frustrated because of small adoption for his plugin. Haven't even heard of that one to be frank, but I see good movement in the ST plugin space for the stuff I use.
But my point was actually the opposite: I'd take a more fleshed out product like ST even if it's not user-friendly (in the community, developer relationship sense), over a user-friendly product thats not as functional, such as Atom etc.
If ST stops serving my needs (which it can serve as long as it runs in the current state, I don't need anything new, except for it to be ported to new versions of OS X), I'm OK. Else I can switch. I've used anything, and I'm a 15+ years Vim user too, so I can always go back to that.
Sublime is a zillion times faster than Atom, and brackets isn't something that enters into the same league as either. I don't see how open-sourcing will help it.