Yeoman is a robust and opinionated set of tools, libraries, and a workflow that can help developers quickly build beautiful, compelling web apps.
I’ve been meaning to link to this tool for quite a while now. At DotJS (which ended about 7 hours ago), Addy’s talk sparked the interest in it again. With Yeoman you can, amongst other things it can do, easily create a new web project — with one command — containing most of the stuff you’ll need. Adding or updating JS libraries/plugins (including dependencies) to your project also is only a matter of typing in a single command.
Uses the aforementioned Bower internally for package management.
Also see Say Yo to Yeoman, which will come in handy to kickstart your Yeoman Command Line Fu.