XML is a “Metalanguage”
Used to define custom tag sets
- Tag sets get called “languages”
- Languages can be built for
- problem domains (journal publishing, textbooks, computer manuals)
- applications (like eBusiness, content-management)
- vertical markets (airplanes, tourist industry, financial)
- information collections (reference works, laws and
statutes, biographies, dictionaries)
- Different markup languages for different information
types
