Tell your customer that Tomcat 5.5 is largely unsupported these days, and that TC 7 has big advantages over TC 5.5. It's your responsibility as a consultant (or whatever capacity you have) to point out such things, even if the customer has a different opinion.
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com
subject: Configuration differentes between tomcat 4 and tomcat5