These free open source web applications provide fast, free, and slick alternatives to expensive business systems.

• Spree
  Slick e-commerce application.
• Community Engine
  Social network services that can be plugged into a larger site or web application.
• Panda
  A web application for uploading and sharing video content.
• RadiantCMS
  A fast CMS for small teams to run websites.
• XLsuite
  All in one Business Management System built in Ruby.
• Albumdy
  a multi-user image gallery system where images can be uploaded, edited & shared.
• ClockingIT
  Project management and time-tracking application.