Send your site users or clients regular email newsletters and track their reaction to them. With HTML or plain text messages, file attaches, links and user behavior reporting.

Shared calendar application with multiple views, meeting management and file attachments. Now with support for International Date Formats.

Include your own search engine on your site pages. The search engine on the Portuguese version of the site is an example

Traditional auctions application. Allows the sale of products by category, bid management, user validation, images, reserved or free base price, etc 
  

Simulate the Usenet newsgroups. Check the newsgroups tab to see an example.
  

News management system with direct input of texts (and one image) by the final users. No dependency on development for data updates