Funy you should write this because I've gone through the same set of problems on my Mac, though it has Snow Leopard. I was helped by a message Jim Robinson posted on this list on January 21.
Try this abbreviated version of his instructions:
Look for (or create) a directory /Library/Java/Extensions either as a child of /Users/$user or as a child of root.
Copy the file saxon(he.jar into that directory
If OS 10.5 works like Snow Leopard, a command java net.sf.saxon.Transform or java net.saxon.Query will find the program whatever directory you're in.
If that doesn't work look at his fuller instructions.
On Jan 25, 2010, at 4:06 PM, amanda rugg wrote: