I was playing around with shaders the other day and found the lack of syntax highlighting in Visual Studio to be a bit annoying. I had downloaded the Nvidia FX composer but it's a bit more complex than I really need. After a bit of searching google I came across InteliShade.NET.

InteliShade seems to have full syntax highlighting and InteliSense for base types. So far the InteliSense support is fairly simple. It will autocomplete object types and function names. It does not detect any variables or structures you've created nor does it give parameter completion on functions. I'm sure this will change as time goes on.

It looks like there's just one guy writing it and also doesn't seem to be open source. I'm sure if there's enough interest he may open things up. I've already begun talking this thing up. It wasn't too long ago Shawn Hargreaves gave a talk at our local XNA user group and he mentioned he didn't know of any VS HLSL sytnax highlighting and urged us to bug the VS team to add it. After finding InteliShade I did send him a quick email through his blog to let him know there is now an option.