There’s a Pascal like language called structured text[0], but that may not be exactly what you’re working for. I hear it’s not used much in production and the tooling for the cheaper hobbyist-tier PLCs don’t tend to support it.
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/