I don't think XSLT intellisense (or debugging) is available in Standard edition. You won't be able to use VS 2003 schemas since XML and XSLT editor are completely different starting with VS 2005.

Mikhail Arkhipov (MSFT):

I don't think XSLT intellisense (or debugging) is available in Standard edition

phizz:

I would gladly pay for a plug-in which provides such a feature (though the cost would obviously have to be significantly less than the difference between VS2008 Standard and VS2008 Pro!)

I think that kind of add-ins could be a violation of the eula, so propably you won't find any. It would be funny that a "cheap" standard/or a free express edition could be converted to a pro or team with cheap/free add-ins, I'm sure that the eula prohibits this

According to the Visual Studio 2008 feature matrix xslt debugging is not available in standard, but there is no info about xslt intellisense(?)

Anyway the pro upgrade price is not much higher than a full standard price, and in fact we are eligible for the upgrade price all time(?!), check this Visual Studio 2008 -Pricing:

Purchase Visual Studio 2008 without an MSDN Subscription

Upgrade Pricing Eligibility

To qualify for upgrade pricing, you must be a licensed user of one of the following products:

• An earlier version of Microsoft Visual Studio
• Any other developer tool (including free developer tools, such as Visual Studio Express Editions or Eclipse)

Upgrade pricing eligibility does not apply for Volume Licensing programs.

Visual Studio is extensible so writing add-in won't violate EULA (and, in fact, may be encouraged). Technically XSL is XML and XML editor with intellisense is provided even in Express editions (web.config is XML with appropriate schema). So technically it is possible to write XSLT schema and give it the XML editor. Schema for 2003 won't work since it is a schema for HTML editor (in 2003 and earlier HTML editor handled XML while in 2005 and later XML is a completely different editor). Have a look here: http://blogs.msdn.com/astebner/archive/2005/12/07/501466.aspx. Perhaps you can simply get standard XSL schema or DTD from W3C site?

I think this is not illegal, maybe this is an installation bug for vs standard(?)

You can put any xsd in that folders (same for vs2005), and the intellisense pick it up automatically.

For example you can download excel2003 xml schema from ms, and put it in that folder. Next time when you start editing an xslt file with excel2003 schema, you get intellisense :)