As a quick introduction:

the .NET framework (basically a set of pre-built code classes that you can use in your own code) can be used for dynamic web pages (ASP.NET) but also for normal desktop apps, for PocketPC apps, to make Windows services and web services.

The .NET programming languages are C# (C sharp), J#, C++ and VB.NET.

The .NET framework is installed by default on all XP machines although a new version (2.0) was released a couple of months ago.

You'll need a coding environment to write your code in (although you could just use Notepad if you're brave). Microsoft Visual Studio is the obvious choice, but not cheap. There are other coding environments you can buy (Borland, ...) and there are even excellent open sources ones (www.sharpdevelop.com).

There is an open source project to port the .NET framework to Linux and Unix (including OSX): http://www.mono-project.com

So why would you care? Chances are that sooner or later you'll bump into a client who is using the .NET framework for their development and wants their FileMaker stuff to integrate with it.

.NET developers can use the open source fmDotNet for that (http://fmdotnet.sourceforge.net).

Thanks Wim :

Garry