From OpenSCADAWiki
Creating a New Module
Modules in OpenSCADA are the shared libraries, which are dynamically connected to the OpenSCADA core at startup or during the program operation. Many of the modules can be disabled, connected and updated during the operation from the module scheduler. Modules can be also builtin-included into the OpenSCADA core during building by an argument -enable-{ModName}=incl to the configure configuration script, what you can learn from the building manual. The OpenSCADA modules can be of seven types according to the presented modular subsystems. For now the modules to OpenSCADA are written in the "C++" programming language, although bindings for other languages may appear in the future.