These AJAX technology was born when I need to make Control Panel with several DataGrids (many change Panels) on one page. User should change, add, delete, sort and filter parameters in one moment and easy save them to server. I understand that PostBack is simply dead way, found some articles about JavaScript sorting, but it was useful only for not paging DataGrids, and very simple sorting like for strings or integers. It cannot help with edit data, and simply I needed more common problem solution.
I knew that ideal solution is in really effective talk between Client and Server.
So my criteria’s were:
1) No DUBLICATES of data transferred to Client and Server
2) It’s must be fully CROSSBROWSER … (some of my users work on Mac)
3) Very simple to INTEGRATE with existing applications, that means NO CHANGES to code, NO SPECIAL helper classes that make for example Scripts. Everything like in usually ASP.NET application.
4) NO JAVASCRIPT if it hard to create, why to do on client when simplier on server
5) It must support .NET 1.1 and .NET 2.0 and maybe Mono or other Servers (like Apache)
6) Working with ANY COMPLEX Server Controls

So it must be easy to create application as though you not afraid some superfluous PostBacks, but that helps you to make site very quickly. Solution was founded – FastPage!