This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
I don't know. I do know that questions of the form "What is the difference between X and Y" are annoyingly vague and the answers are not likely to be helpful. Why don't you ask a question like "I want to do (insert your requirements here). Should I be using JTA or JTS or what?"
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