Masem, Cool question ++. I'm currently using the following:

• Xalan XSL-T engine from the Apache group, C++ version works, but the Java one doesn't like me.
• Instant Saxon, from Micheal Kay, Java standalone job.
• Matts excellent XML::LibXSLT along with other XML tools.

I have found that the Perl interface in LibXML and LibXSLT are pretty powerful and fast, and seem to work okay, they can even hadle XSLT jobs that MSXML and hence XML Spy can't.

For my sins I'm using a home grown Templating system, but I plan to migrate to AxKit, which seems to do everything I could ever want....

On the books front, I have the following:

• "XSLT" ISBN=ISBN 0596000537 which seems okay
• "XML in a Nutshell" ISBN=ISBN 0596000588 which is a typical compact ORA nutshell
• "XML Pocket Reference" ISBN=ISBN 1565927095 there is a new edition of this
• There is also an ORA "Learning XML" ISBN=ISBN 0596000464, and a Wrox "XSLT Programmers Reference" (by Michael Kay), ISBN=ISBN 1861005067.

Good luck whatever you do....