We are using an older version of Prince (7.1). Is there an easy way I can determine what new features/performance improvements are in the releases after the one we are using? I couldn't find this information in the user guide and it would help me make the case for upgrading.

Look at roadmap.
http://www.princexml.com/roadmap/

Jim Albright
Wycliffe Bible Translators

Some feature highlights include:

• HTML5 support
• JavaScript support
• CSS3 Transforms
• PDF attachments
• ::first-line selector
• column-span: all

On top of that Prince is faster, and includes dozens of bug fixes and conformance improvements making it more compliant with web standards and interoperable with browsers.

The complete list of changes is in the release notes.