Please see the CHANGES_2.2 file, linked from the download page, for a full list of changes. A condensed list, CHANGES_2.2.15 provides the complete list of changes since 2.2.14. A summary of security vulnerabilities which were addressed in the previous 2.2.14 and earlier releases is available:
Apache HTTP Server 2.2.15 is compatible with Apache Portable Runtime
(APR) versions 1.3 and 1.4, APR-util library version 1.3, and APR-iconv library version 1.2. The most current releases should be used to address known security and platform bugs. At the time of this httpd release, the recommended APR releases are:
* Apache Portable Runtime (APR) library version 1.4.2 (bundled),
or at minimum, version 1.3.12
* ARR-util library version 1.3.9 (bundled)
* APR-iconv library version 1.2.1 (only bundled in win32-src.zip)
Older releases of these libraries have known vulnerabilities or other defects affecting httpd. For further information and downloads, visit:
Apache HTTP Server 2.2 offers numerous enhancements, bug fixes, and performance enhancements over the 2.0 codebase. For an overview of new features introduced since 2.0 please see:
This release builds upon and extends the httpd 2.0 API. Modules written for httpd 2.0 will need to be recompiled in order to run with httpd 2.2, and may require minimal or no source code changes.
When upgrading or installing this version of httpd, please bear in mind that if you intend to use httpd with one of the threaded MPMs (other than the Prefork MPM), you must ensure that any modules you will be using (and the libraries they depend on) are thread-safe.