Alternatives to XML?

[Peter Otten]

Frank Millman wrote:

>> As you have to keep the "<", why bother?
> 
> If you mean why don't I convert the '<' to '<', the answer is that I do
> - I just omitted to say so. However, explicit is better than implicit :-)

Doesn't that make the XML document invalid or changes it in an irreversible 
way? How would you know whether

"<foo><bar/></foo>"

started out as

"<foo><bar/></foo>"

or

"<foo><bar/></foo>"

?