The Apache Software Foundation released a maintenance update to the 2.2 httpd branch. Version 2.2.2 is now considered the gold standard that outfits running Apache should be using. It is available for download, here.
As usual, the full cadre of release notes are online. Changes have been made to mod_deflate, so that it works correctly in an internal redirect; mod_proxy_balancer, which now initializes members of a balancer correctly; mod_proxy, so that it no longer releases connections from the connection pool twice; prevent the reading uninitialized memory while reading a line of protocol input; mod_dbd, whose defaults have been updated and error reporting improved; and mod_dbd, which creates its own pool and mutex to avoid problem use of process pool in request processing.
Version 2.2 was initially released in December 2005. Core enhancements include, refactored authentication and authorization modules; a host of changes to mod_cache, mod_disk_cache, and mod_mem_cache; a simplified and modularized default configuration layout; and graceful shutdown for prefork, worker, and event MPMs. Changes were also made to the mod_auth, mod_authnz_ldap, mod_authz_owner, mod_version, mod_info, mod_ssl, and mod_imagemap modules.
The ASF also recommends anyone still running the 2.0 or 1.3 forks that does not plan to upgrade be sure to patch to 2.0.58 and 1.3.37, respectively.