In Windows, the install instructions in the readme should work. You may or may not have to set environment variables, I don't remember if I had to do that, but I don't remember having any issues. You'll probably want Git and MinGW as well.
If by "browse and install packages" you mean for Arc, you can't, yet.
I use Sublime Text with the syntax set to Lisp (which works well enough) and the terminal plugin, so I can open a Powershell prompt with Ctrl-Alt-T.