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.
Everyone from startups to non-profits to enterprise organizations are using Rails. Rails is all about infrastructure so it’s a great fit for practically any type of web application Be it software for collaboration, community, e-commerce, content management, statistics, management, you name it.
Rails works with a wealth of web servers and databases. For web server, we recommend Apache or lighttpd, running either FastCGI or SCGI, or Mongrel. For database, you can use MySQL, PostgreSQL, SQLite, Oracle, SQL Server, DB2, or Firebird. Just about any operating system will do, but we recommend a ‘nix-based one for deployment.
If you need hosting, TextDrive is the official Ruby on Rails host, offering fantastic plans with a knowledgeable staff. Whether you need shared or dedicated hosting, these guys are experts in Ruby on Rails. For alternatives, see the wiki for a full list of Rails web hosts.