From the Padrino’s site:
Padrino is a ruby framework built upon the excellent Sinatra Microframework. Sinatra is a DSL for creating simple web applications in Ruby with speed and minimal effort. This framework makes it as fun and easy as possible to code increasingly advanced web applications by expanding upon Sinatra while maintaining the spirit that made it great.
The Ruby community has plenty of web frameworks at this point. Padrino — self-described as “The Elegant Ruby Web Framework” — is interesting because it’s built on top of Sinatra, it’s highly modular, quite fast, and provides a drop-in admin interface. It fits between Sinatra and a large framework like Rails.
If it wasn’t for the fact that Rails 3 is about to be released, Padrino may have had a fighting chance at acquiring a good market share within the Ruby community. Rails 3 is here though, and it too is very modular and fast. Plus, it’s hard to beat the huge ecosystem that’s already built around it.
That said, the presence of an admin interface, a la Django, and the Sinatra core are definitely inviting features. Check out their documentation and screencast, to see if you think it’s worth considering for your own web development needs.