The Apache HTTP Server Project is pleased to announce the release of Apache HTTP Server, version 2.2.13. This release represents ten years of innovation by the project, and is recommended over all previous releases!
For details see the Official Announcement and the CHANGES_2.2 and CHANGES_2.2.13 lists
Add-in modules for Apache 1.3 or 2.0 are not compatible with Apache 2.2. If you are running third party add-in modules, you must obtain modules compilied or updated for Apache 2.2 from that third party, before you attempt to upgrade from these previous versions. Modules compiled for Apache 2.2 should continue to work for all 2.2.x releases.