The words of one user sums it up " XMLMax is like, wow, this thing
is many orders of magnitude faster than anything else, and handles
any size xml."

See for yourself. Download the 30 day free trial with no functional
limitations and no registration.

http://www.xponentsoftware.com

XMLMax uses only 20Mb of memory, regardless of xml file size, and you
always get a treeview.

In five seconds XMLMax will parse, syntax check and display a 150 Mb
xml file in its virtual treeview; a 3.7Gb file in three minutes.

Instantaneous reloading of the same XML file, regardless of size.

Other features include:

syntax checking * schema validation * markup protection * auto
complete * namespace aware

XPATH query * XSL transformation