> I just tried Saxon parser after increasing the initial/max 
> Java heap space to 512M and it worked with even a 74MB file, 
> but took about 28 minutes to finish. 

That does seem quite high, given that Saxon can do an identity transform on
a file of that size in something close to 28 seconds. I wonder if there is
some other problem in your code (are there parts you haven't shown us?). Is
the performance linear with document size?

Michael Kay
http://www.saxonica.com/