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.
1.4 is version 1 and 2.4 is the version 2 Basically they just built up the library with a lot more options esp with schema if I remember right. Here is a link to show you the features and other things of version 2 http://xml.apache.org/xerces2-j/ and here is the same thing for version 1 http://xml.apache.org/xerces-j/