Why does Octopress require the Sinatra gem?

Question

I'm currently getting started with Octopress and just cloned the repo. I noticed in the Gemfile that it requires the Sinatra gem.

Why does Octopress need Sinatra? I assume it's only for development.

Answer 1

It's Used for Previews

At the time of this writing, Octopress has a :preview rake task that invokes rackup, which in turn invokes Sinatra. Sinatra is used to serve up the pages on your localhost for viewing.