Latest Release is 1.3.1. This needs a Java 8 runtime environment.

Release 1.3 can be used with older versions of Java. Note however
that Java version 7 public updates already stopped in April 2015, so it
might be time for also you to update to the newer version. After all, Java 9
will be there soon!

Apart from the Java version which is supported, there is no 
essential difference between versions 1.3 and 1.3.1.