Afterweb

  Platform   deCarta ESRI GoogleMap MapQuest Scalability + + + + Internet/Internal Internet (hosted) Internal and Hosted Internet (hosted) Internal and Hosted SDK, Ease of development Navigation SDK, rapid deployment for hosted solutions, no code needed for simple apps (using Wizards) ArcGIS for desktop, client and web dev. KML, javascript SDK SDK Support + + good public forums + Development Languages JavaScript API, WS Java, JavaScript, C++ for WinCE, Win XP, JSP, ASP, ASP.NET, ColdFusion, ArcXML, WS, Eclipse dev environment JSP, ASP, ASP.NET, PHP, JavaScript lib JSP, ASP, ASP.NET, PHP, XML, WS Major Markets Telecom, Wireless Goverment, Public works mostly Consumer, Google MapEnterprise for

Here is the best intro into the Facebook architecture description: http://www.slideshare.net/davidzhuang/facebook-platform-tech/ and API link: http://20bits.com/2007/06/04/an-introduction-to-fbml/ and a sample (better than official one) http://gallery.menalto.com/node/65135