Richard Sim, Senior Product Manager for Windows Live Hotmail posts an interesting and comprehensive list of what the Hotmail team has accomplished since starting the project almost two and a half years ago. As he says, “(t)he UI and features that are visible to end users only scratch the surface of what we’ve done”.  Sim’s list:

• rearchitected the entire service from scratch,
• swapped out the backend storage infrastructure (literally swapping out old boxes for new ones)
• instrumented user actions,
• created new ways to serve advertisements,
• developed new advertising products,
• created a scalable and flexible mail platform to power email for universities and other partners,
• managed a large scale beta process with a continuous user feedback loop,
• redesigned our product development and deployment processes,
• streamlined our signup flows,
• opened up Outlook client access for ALL free users (coming very soon),
• created a Windows Live Contacts (subscribe to contact updates) service,
• created a new selection paradigm for email client applications (dynamic checkboxes) which has been eventually adopted by Yahoo Mail Beta,  
• and released a new safety bar to educate users about the context of every mail that arrives in his/her inbox

“Oh, and of course, rewrote the entire UI and released dozens of great features.”