I'm curious, too. Also how does it compare to Spray? https://github.com/spray/spray

lightweight as in activerecord and all the other things aren't bundled in by default. you bundle what you need. sinatra doesnt assume that you need an orm or template language. think of sinatra as a domain specific language for creating websites, but you could tack on orm or templates as you see fit.

Does one thing or a few and does it well.

I haven't checked, but for starters you possibly could look at the download size.