After a couple of weeks, I still have not been able to reach someone over at the jEdit project. So I still don't know about the license of jEdit's syntax definition files. While jEdit is GPL code, the definition files are supposably not. XML files are neither sourcecode, nor could they be executed or so.
The point is that while jEph may be used with non-OSS projects (LGPL), you might not be allowed to use the syntax files in that way.
One hint that those files /might/ be public domain is nother project  I found recently, which is licensed as public domain as well.... read more
jEph is a brand new approach for PHP-based syntax highlighting. It does not have it's own format for syntax definition files, but uses the files from jEdit instead. This way, jEph relies on an established and very huge set of definition files. The translation from jEdit's XML format to PHP code is done by an XSLT stylesheet.
The current code is already working, although it still contains some bugs. There is a working demo on the project page http://devel.webmasterpro.de/projects/jEph/index.html... read more