Here's an interesting link for those of you who don't ready my blog (shame on you by the way
).
Gaston Milano has created a T4 editor that plugs into VS2005. It does colorization of template code versus output text, keyword colorization, and some intellisense. It should prove very useful for those of you writing T4 templates.

T4 Text Template Editor for VS2005
Josh Cochran
Be sure to give your templates the right extension otherwise the syntax isn't highlighted.
Otherwise try out this one: http://modelisoft.dyndns.org/Nouveau/T4LangPackage.aspx
Hope it helps,
Gerben.
Selim
Does anyone know of syntax documentation for T4 text templating
Stefanie
Hi,
Did you check the documentation that comes with the DSL Tools You can find it there : ms-help://MS.VSCC.v80/MS.VSIPCC.v80/MS.VSSDK.v80/dv_dslconrd/html/74a0a748-5b11-4999-8bea-49572967827d.htm
(You can also find the same documentation on MSDN).
Is this what you were looking for
Edward
johnlayer
Jeff Wang
Anyone able to give some step-by-step guide of setting it up It seems to be a very useful tool, that would ease some of my grievances with these templates.
Shaik Abdullah K
Sounds like the package doesn't automatically register in the Exp hive. One thing you can try is using the "Reset the Visual Studio 2005 Experimental hive" shortcut in the Start menu under All Programs->Visual Studio 2005 SDK.
Note that this will clobber your existing Exp hive, and replace it with the contents of the normal hive (which now includes the T4 editor). Generally the clobbering is fine, because DSL projects and other VS SDK project types will re-register themselves in the Exp hive on the next build. However, if you have per-user settings in the Exp hive you'd like to save, you should export them before resetting (settings in your normal VS hive will not be affected).
Thanks,
Grayson
Jakob Røjel
it works like a charm now!