Alpha Five is a powerful database and Web applications server and development environment that has been around for many years and continues to get more powerful but not at the expense of ease of use. There are numerous tutorials

You can watch my screencast video here: http://webinformant.tv/alpha5.html

We tested Alpha 5 v10 on a Windows XP running SP2 in February 2010.

Documentation, copious code examples and videos:
http://docs.google.com/View?id=d52ghw8_92f9r2m4dx
http://www.ajaxvideotutorials.com/videos/help/01intro/
http://65.75.250.238/webApplicationDemoV10/default/index.a5w

Alpha Five v10
http://alphasoftware.com/products/v10/
70 Blanchard Road,
Burlington, MA 01803
781.229.4500

Prices: Developer $349
Application Server $599, both for $799
Unlimited Runtime licenses $599
Windows XP or later required with at least IE v7 or Firefox 3.0