Updated 19 January 2015 to fix Java 8 support. The previous versions gave an "Annotation processing got disabled, since it requires a 1.6 compliant JVM" error.
Updated 21 March 2016 to newest version (from R-4.4.1-201409250400 to R-4.5.2-201602121500) as part of updating Java Mode
Finally, the archive site contains additional jars for the 4.5.2 release, including the JDT Core Batch Compiler (ECJ):