VAX is an add-on to Visual Studio that provides a number of features that helps developers be more productive. My favorite feature is the Intellisense filtering. Intellisense is one of the greatest productivity enhancements for developers since the advent of the IDE, however, it can sometimes be difficult to find what you want in the list. VAX filters the Intellisense so that you can find what you want.
For instance, if you have a class that has hundreds of methods including one called DoSomethingReallyCool and you need to call it but can only remember that it contains the word 'Cool' somewhere in it, with typical Intellisense, you have to search every single member of the class. However, with VAX, you just type in 'MyVariable.Cool' and Intellisense will filter the list to include all the members with the word 'Cool' in it (the home page of their website shows this very well).
Using this filtering technology, you can also type 'MyVariable.DSRC' + Tab and it will auto complete for you! Once you become used to this you will find yourself typing far fewer characters. It's like snippets without having to setup snippets.
The Intellisense filtering makes VAX worth every penny of the cost, however, it also includes some other great features...
- Spell Check - Who doesn't need a spelling checker? VAX will check your strings and comments. It seems to be smart enough to recognize code names in your comments.
- Enhanced Code Element Visualization - Adds more colors and styles (like bold and italics) to different code elements.
- Reference Navigation - Provides the ability to navigate to code that references a class, class member, or variable. Very handy when trying to fix a bug in somebody elses code :).
VAX also includes a bunch of other features, but these are the ones that I use most often and have really helped me be more productive. If you like productivity tools, this is definitely one that you should be using.