Symphony.

After my upgrade to Lion, I was disappointed to find that the available tools for testing XML & XSLT no longer worked as support for PowerPC apps has been discontinued.

I Dismayed. Until today.

There's a neat little utility called coderunner that allows you to test and run different code types, including XSLT.

In teh preferences, just set up a new language as per the this screenshot (exactly). When you want to run code, use run with input and paste in your XML into the stdin input box.

I'm getting in touch with the developer to add syntax highlighting for xml based languages, so we can hope for better looking code.

That aside, this is really neat.