OT: Less-restrictive alternative to XML and XML visualizers?

[Nick Sabalausky]

I have a need for an inexpensive (preferably freeware or open-source, 
obviously), alternate to using XML and an XML viewer (such as MindFusion's 
XML Viewer). The main problem with XML is that I need something that will 
allow node names to contain any arbitrary text character (or at least just 
the ascii symbols such as parentheses, comma, etc). Any ideas?