A freeware XSLT testing tool with a nice UI.

Digital Identify Application

XSLTester is a free source testing tool for development and debugging of XSL Transforms. You can load and edit XML and XSLT files, transform in place and view the result in multiple formats.

Using vbAccelerator Code

The application uses a variety of vbAccelerator controls and code to build the UI for the tester.

The Site

VBXML's site can be found at http://www.vbxml.com/. You can download XSLTester from http://www.vbxml.com/xsltester/disclaim.asp