X10 2.1 has been released on the X10 website
Students may continue to use X10 2.0.6 if they wish, however I would strongly urge that you shift to 2.1. There are many changes in 2.1 that simplify programming, particularly multi-place programming. These will be covered in class on Monday, Oct 25.
The language manual can be found here. Please check the Change Log - Changes from X10 v2.0.6 (Appendix A.1). This describes many changes in the language from 2.0.6 to 2.1. The ones that will concern the class most are the changes in A.1.1 (object model -- in particular I will no longer need to discuss place types in class for the global object model), changes in the main method signature (A.1.5), and A.1.6 (assorted changes).
The new version of X10DT is available here.
The code being used in class has been converted to X10 2.1 and committed. You will find it in the pppp10-21 project in SVN.