JEdit version 4.2 is the latest stable version. JEdit is a java-based program and you will need to have a Standard Edition of Java installed and running on your machine. Another option I often use is the XML plug-in in Notepad++. Setting up JEdit XML Plug-ins Using JEdit Editing XML Validating XML Useful Links Setting up jEdit. Xerces is available for Java as well as for C++.
One option is to use Apache Xerces Parser. Here are two of these which I find useful.
#Validate xml in jedit update
Add this URL to your Eclipse Installation to reach this solution's update site. Ive been evaluating jEdit lately and considering it for both my own personal editor to replace BBEdit and as a text editor for some hands-on XML classes.