Microsoft .NET
.NET is Microsofts latest and greatest framework for creating software applications.

.NET has the unique advantage of being Microsofts development platform.  Meaning that if you want to write an application for windows, then you will be able to do it faster, better, and easier than using any other development platform.  Since the code is designed to run natively on Windows, creating Windows applications is simple and effective.

.NET also provides a set of frameworks for designing on the web dubbed ASP.NET.  ASP.NET is the successor to ASP (Active Server Pages) and has made a large step forward since the early days of server side processing.  ASP.NET provides API's to create web pages, send e-mail, create XML web services, manipulate XML using XSL/T, and create rich client applications.

With the release of the next  version of the .NET framework just around the corner, and a new Windows operating system close on it's heels, there are bound to be some great thing going on with Microsofts development platform.