Download Cooktop

Cooktop is an editor and development environment for XML, DTD, and XSLT documents
Cooktop is a Windows application
Best of all, it's free!
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
Choose Open from the File menu
In the File/Open dialog under "Load the file in:" select "Current Window"
Open an XML file
Open an XSL file using File/Open
Set run-time parameters via Options/ All Options/ XSLT Properties/ Run Time Parameters
Press one of the XSLT buttons in the toolbar or choose from the XML menu.