Count Instances of Process or Application in C/C++

This article describes how to count the number of instances of a process that are currently running on the system. It is written in C++ for Windows, but could be ported to other systems and languages easily. (Linux, Visual Basic/VB, C, Unix, MacOS) The system just needs to support interprocess semaphores. The idea can be extended to count any resource, such as a thread, file, data structure, or network object.