We've released Activiti 5.16.4 and that includes bug fixes, but also 2 bigger features.
We've introduced a new lock free job executor that improves the scalability of the job execution with magnitudes. You can read more about the new job executor here https://github.com/Activiti/Activiti/wiki/Notes-on-the-new-Actviti-Jobexecutor-(Oct-2014).
Note that the default job executor is still the old job executor, so you need to explicitly enable it before it will be used. The new job executor only supports non-exclusive jobs right now. Exclusive job and suspended process instance support will be added in the next Activiti release.
Another change is the move from the Restlet framework to the Spring MVC framework for the REST services implementation. The REST API urls haven't changed though, so all REST clients should still be working ok. We did remove the deprecated legacy REST services though. Let us know if you run into issues due to this removal, but all data should be available through the other REST services. A benefit of moving to Spring MVC is the integration with Spring Security, so it's easier to configure authentication. Also, we'll be introducing an Activiti Spring boot module in the next Activiti release, which makes it easy to add Activiti to a Spring boot application. You can already see more info here http://www.jorambarrez.be/blog/2014/09/29/webinar-on-youtube/ .
You can get the new release via Maven central, the download page on the Activiti website, and our Activiti Github repository. Enjoy!