TeXMLMate

I am a fan of TextMate for many reaso . The biggest reason is the active developer community that surrounds it. Not only does Macromates continue to dream up new features, others are extending the program in a number of very cool ways.

TeXMLMate is a very cool XML palette that enables you to do a number of things with XML documents in TextMate. You can validate XML right in TextMate with TeXMLMate, and you can even validate agai t a schema you have defined. If you find yourself editing XML often you should look into TeXMLMate.