Microsoft Visual C++ file
APS is a file extension for a binary file used by Microsoft Visual C++. APS files are binary versions of the Visual C++ resource file that exists to reduce loading time with graphical components in a program. The Visual C++ resource files aren’t read directly by the resource editor, yet the APS file is. APS files only contain symbolic data which is useful to the program. APS files can be opened by Microsoft Visual Studio.
Learn more about .APS files:
See an introduction to Visual Studio 2010.
Visit the Visual Studio web page.
Learn about Visual C++ at ITKnowledgeExchange.com.