If you are playing with the just released Visual Studio 2010 beta 1 you can’t miss the Regex Editor extension which provides syntax coloring, IntelliSense, support for testing the expression as you write it and support for saving it for reuse from another project. It does also include a built-in list of common expressions ready for use.
You can install it with a few clicks by going to Tools->Extension Manager->Online Gallery and search for “regex”, click “Install” and you’re done.
If you’re an old fashioned guy who likes to be in control of what’s going on in your box, then you can download the VSIX file (btw, this is the new VS 2010 format for deploying extensions) from here (look for the Download button) and double-click on it to install.
I’m including here a few screenshots of how the Regex editor in action:
If you’re into writing VS extensions (or if you’re just curious enough) you can go to the Editor Samples project where you will find source code for this extension (among other extensions) and you can learn about some of the new extensibility points used by the Regex editor.