[slopdo]

Structured Text is one of the programming languages at Part 3 of the International Standard IEC 61131 for Programmable Logic Controllers [0]. In my (european) experience it is commonly used in production.

Later, IEC 61499 for Distributed Systems [1] extended the IEC 61131 with (among others) event-driven control.

On the open source ecosystem, Eclipse 4diac [2] might be interesting as it provides a full PLC framework including IDE and Runtime Environment.

[0]https://en.wikipedia.org/wiki/IEC_61131-3 [1]http://www.iec61499.de/ [2]https://www.eclipse.org/4diac/