Good looking software

Here are some software companies that I've seen interesting products from.

• VMWare: The first and still best virtualization
  
• Atlassian: Makers of JIRA and Confluence both very good products.
  
• Alfresco: Impressive looking open source content management package
  
• Zenoss: Open source Zope based monitoring
  
• OpenQRM: Interesting data center virtualization with full linux process migration