Why is XML such an important development?

XML allows the flexible development of user-defined document types.

It provides a...

• robust
• flexible
• non-proprietary
• persistent
• verifiable
• cross-platform
• cross-language

...file format for the storage and transmission of text and data both on and off the Web; and it removes the more complex options of SGML, making it easier to program for.

XML removes two constraints which were holding back Web and Electronic Information developments:

• dependence on a single, inflexible document type (HTML) which was being much abused for tasks it was never designed for;
• the complexity of full SGML, whose syntax allows many powerful but hard-to-program options.