- Unicode in XML and Other Markup Languages
- UTF-8 and Unicode FAQ
- SMIL Tutorial - w3schools.com
- DocBook: The Definitive Guide
- Introducing DocBook
- DocBook.org Home Page
- MathML 2 Reference with Examples
- Relax NG Home Page
- Relax NG Tutorial
- Relax NG Compact Syntax Tutorial
- XML Schema 2001 and Relax NG Tutorial
- Relax NG Reference
- XUL Programmer's Reference Manual
- XUL Tutorial
- XUL Element Reference
- XUL Object Reference
- XPCOM Reference