Tomcat 6.0.35 currently has ECJ version 3.7 (3.7.0) in it.

Tomcat 7.0.25 has ECJ version 3.7.1.

After discussing with Konstantin Kolinko on the developer list earlier today, he found that ECJ 3.7.2 had been released and put it in the libs directory for the next version of Tomcat 7, but not Tomcat 6.

Consider this my official request to do the same for Tomcat 6, and upgrade it to ECJ version 3.7.2.

Reasoning: Tomcat 7.0.25 can run on Java 7 out of the box, and with a simple change to compileSourceVM and compileTargetVM in $CATALINA_BASE/conf/web.xml can compile JSPs for Java 7. Tomcat 6.0.35 can also run on Java 7 out of the box, but changing compileSourceVM and compileTargetVM to Java 7 will not work, because ECJ did not support Java 7 until ECJ 3.7.1.

Cons: I can't see any reasons (off the bat) NOT to do this. It's possible other people might know of reasons not to upgrade the next version of Tomcat 6 to ECJ 3.7.2.