I didn't actually realise this until it was pointed out; if nothing else, mandatory automatic memory management really hurts its usefulness for a lot of the things that people still use C++ for.
I use GOPATH only inside of a wrapper script that sets GOPATH to the directory for the current project. All libraries are stored alongside my project code in source control. I use go get when adding/changing libraries, but remove the .git folder when doing so.
In the recent past, even with a premier paid account on GAE, getting a specific quota raised took a few days and was apparently a non-trivial operation.
Yeah, what's amazing is that they didn't charge us to increase the limit. It's also pretty awesome that their android push notification service has no quota and is free.
librsync is a library for building rsync workalikes. It is not compatible with rsync itself.
librsync and the rdiff binary that wraps it can create a signature from a destination file, create a patch from a signature and a source file, and can apply a patch to a destination file. And that's about it. librsync doesn't concern itself with the networking. That's up to you.
rdiff is a thin wrapper around librsync. librsync can easily do anything rdiff can do, without having to fork a new process. You might wish the rsync executable were built this way, but it is not.
Sketch is on it's way to being what Illustrator should be. It's still a little buggy at times, for instance, you can't export things at high resolution and the workaround, resizing a group of objects, rarely works correctly.