If you pay attention to nodejs world & suddenly find yourself using 3 version of node simultaneously, you probably may start thinking about a version manager.
There are some existing ones, like nvm & n. They are nice, but both are written in bash & may require a periodic update after a new node/iojs release.
What I want from the 'manager' is that it doesn't integrate itself w/ a shell & doesn't require a constant updating.
A 'non-updating' feature resolves in a drastic code simplification: if a version manager (VM) doesn't know how to install a new node version whatsoever, then you don't need to update its code (hopefully whatsoever too).
A non-bash requirement dates back to rvm, which has been redefining cd for us since 2009. It doesn't mean of course that a VM written in bash would obligatory modify built-in shell commands, but observing the rvm struggle w/ bash, have discouraged me from sh-like solutions.
The VM should be fast, so writing it in Ruby (unfortunately) is not an option, due to a small (but a noticeable) startup overhead that any ruby CLI util has. Ideally it also should have no dependencies.
This leaves us w/ several options. We can use mruby or plain C or, wait, there is Golang! In the past its selling point was a 'system' language feeling.
Well. I can tell that it's not as poignant as Ruby for sure, but it's hyper fast & quite consistent. It took me roughly a day to feel more or less comfortable w/ it, which is incomparable w/ a garbage like C++. Frankly I was surprised myself that it went so smooth.
Back to the YA version manager for node. It's called nodever, it uses a 'subshell' approach via installing system-wide wrappers & it's a tiny Go program.