Detect browser XSLT support in PHP

[devbanana]

Hello,

I am creating a framework, and for the templating, I decided to use XML and XSLT.

The thing is, I've heard that XSLT can be a bit intensive for larger documents, and it might hurt performance. So, I was thinking of detecting if the user's browser supported XSLT, and if so, just have the browser do the transform. Otherwise, PHP could do the transform.

Here's the question:
[list]
[*]Is XSL an accepted standard so much so that it would be safe to assume the browser has XSLT support? it has been around since 1999, anyway.
[*]If not, then how would you detect this in PHP? I'm thinking if I just check the HTTP_USER_AGENT, I might then be able to compare that to known user agents that do support it.
[/list]

Thanks,
Brandon