Apache Portable Runtime

The Apache Portable Runtime (APR) is a supporting library for the Apache web server. It provides a set of API's that map to the underlying operating system. Where the OS doesn't support a particular function, APR will provide a replacement. Thus, the APR can be used to make a program truly portable across platforms.

APR was originally a part of Apache, but has now been spun off into a separate project of the Apache Software Foundation, and is used by other applications to achieve platform independence.

The range of platform-independent functionality provided by APR includes:

Memory allocation and memory pool functionality
Atomicity operations
Dynamic library handling
File I/O
Command argument parsing
Locking
Hash tables and arrays
Mmap functionality
Network sockets and protocols
Thread, process and mutex functionality
Shared memory functionality
Time routines
User and group ID services

Similar projects

Glib provides similar functionality, but is much more extensive, supporting many more data structures and OS-independent functions.
NSPR is a cross-platform abstraction library used by the Mozilla project. In addition to the usual basic services, it also provides graphical user interface (GUI) functionality.
Adaptive Communication Environment (ACE) is an object-oriented library similar in functionality to APR. It is widely deployed in commercial products.
WxWidgets is an object-oriented cross-platform GUI library that also provides abstraction classes for database communication, IPC and networking functionality.

External links

http://apr.apache.org/ – The APR website
http://apr.apache.org/docs/apr/ – APR programming documentation
http://apache.org/ – The Apache Software Foundation website