Develop your web application decoupled from the Liferay Java stack
Rails-portlet was originally developed to run a Rails app inside Liferay JSR286 portlet container. It is not specifically tied to either Rails or Liferay, although it is being developed for this particular combination. Currently it supports Liferay 5 and 6, and the helper utilities work with Rails 2.
Rails-portlet has been successfully deployed in large systems and can be considered stable.
Get started with Rails 2 and Liferay 6
If you want to build a Rails app and run it inside Liferay, start from the setup guide.
Not running Liferay?
Portals with proper support for the JSR286 spec (portlet 2.0) should technically work.
Unless Rails is your cup of tea?
The helper utility Caterpillar is a Ruby gem that can run without Rails, although majority of it is a Rails plugin. Future versions may contain functionality to parse the portlet XML outside the Rails environment. You need to install the rails-portlet jar file and write the portlet XML configuration manually. Refer to Caterpillar documentation and source code. ;)
What about Web Proxy Portlet or portletbridge?
Read this blog post for comparison.
How to contact the project?
If you need support