Web Application Toolkits are a set of ready to use kits with samples and controls that help ASP.NET developers quickly work out common web scenarios. While you’ll find more reusable components if using ASP.NET on your site you can still take advantage of the samples and scripts to reuse these on non-ASP.NET sites as well. Really well worth a look!
This is the collection of toolkits available today:
Go to microsoft.com/web for details and downloads: http://www.microsoft.com/web/webapptoolkits/