What is a Plugin?

A plugin (sometimes referred to as a driver) allows people to add custom
functionality to Mach3/Mach4. Plugins are written as .dll files in programming
language in Mach3. Plugins for Mach4 include both a .sig and .m4pw file. They are
primarily used to enable Mach3/Mach4 to work with hardware devices (e.g. external
motion controllers), but can also be used to add functionality (e.g. Mach3’s Flash
plugin) or extend existing functionality (e.g. Mach3’s Jcode plugin).
Visual C++ 2003 is required to create Mach3 plugins.v