Btw, what is the most mature GUI toolkit for Go nowadays? Any experience using gotk3?

I'd say the Go-QML is the most mature.

Agreed!

Also, Go-QML and gotk3 are probably the only two golang non-web, traditional "widget" type UI projects worth exploring if you want something to just build apps and not spend a ton of time hacking the library itself to do what you want.

There may be some decent ones I'm not aware of but all the ones I've looked at other than Go-QML and gotk3 are some combination of abandoned, not yet ready for prime-time and/or horribly flawed at some basic level of their design.

I'd say Go-QML as well, not just because it already works quite well but because it's actively developed and maintained. I've been following the project on GitHub and Gustavo Niemeyer has done an impressive work so far, and is quick to deal with pull requests and to answer issues.

The custom OpenGL-based toolkit I use in Conception-go is not mature at this time; much work remains.

There is no such thing as "chrome native support". Go has a NaCl port, but that doesn't support Chrome.

On this note, NaCl support is being included in 1.3: http://tip.golang.org/doc/go1.3#nacl

Or cross-platform OpenGL ES 2 apps. Just like Android and iOS do it. ;)

Error 522 Connection timed out

Sorry about that. It seems to be working now. I was hoping CloudFlare would relieve the server enough for it to remain working fine despite the traffic. I'll have to move over this blog to a more reliable setup.