The ePublisher platform rests on top of the .NET platform.  Even though the bulk of the ePublisher processing is done with XSL, you can opt to process items with any of the .NET CLR languages rather than XSL. I published a wiki article which includes an ePublisher project that demonstrates processing content paragraphs with JScript .NET.   I am curious if the barrier to customization in ePublisher is the XSL.  Since Javascript is ubiquitous, this sample provides an alternative to XSL.