Ruby On Rails

Ruby On Rails∞ is "a full-stack framework for developing database-backed web applications according to the Model-View-Control pattern. From the Ajax in the view, to the request and response in the controller, to the domain model wrapping the database, Rails gives you a pure-Ruby development environment. To go live, all you need to add is a database and a web server."

Getting Started
Deployment of an existing application
Notes About Using Textile
More Notes on deployment of an existing application
Deploying a new Rails 2.1.0 app

Just Ruby

If you would like to use Ruby without the Rails framework (i.e. just like PHP is used) then you probably want to learn about eRuby. Although eRuby does not offer the same framework and structure that Ruby on Rails does, it makes it easy to upload a ruby script file (e.g. an "rhtml" file) that "just works" once uploaded. There is no need to start or stop a server like Rails.

Getting Started