Major Description
Recently, Activiti 5.11 has been released [1]
Considering the high number of bugfixes included [2] and nice features like as the availability of the web Activiti modeler and proper support for MS SQL Server, it is definitely worth upgrading.
[1] http://bpmn20inaction.blogspot.be/2012/12/activiti-511-released.html
[2] http://jira.codehaus.org/secure/IssueNavigator.jspa?reset=true&jqlQuery=project+%3D+ACT+AND+fixVersion+%3D+%225.11%22+AND+status+%3D+Resolved+ORDER+BY+priority+DESC&mode=hide