Cooktop is an editor and development environment for XML, DTD, and XSLT documents, this tool run under Windows only. And, it's free!

Here some features on Cooktop:
Color-coded XML, DTD, and XSLT editing
Check well-formedness and validate
Stylesheet testing with almost any XSLT engine
XPATH testing
Customizable "Code Bits" library
XML formatting via Tidy
Small download, small footprint

System Requirements
Version 2.5: NT4/2000/XP Only
Version 2.2: 95/98/98SE/ME/NT4/2000/XP


Homepage: http://www.xmlcooktop.com/
Sizes: 1.47 MB
Download: XML Cooktop 2.5