SchemaSpyEditor allows you to edit metadata for SchemaSpy Graphical Database Schema Metadata Browser. This tools allows use to easily edit XML metadata files without risk to damage them.
AG101 is a java-based visual XSL editor/debugger built on the Pollo XML editor (pollo.sourceforge.net). It has extensions to a regular expression library. It also has the ability to pipe XSL transforms one to another and store and reuse those pipes.