Ladder editor and debugger
JQM - Java Quine McCluskey for minimization of Boolean functions.
Open source PLC IEC61131 Software Componet with c++ source codes
Software PLC/HMI system.
Free ladder & sequential (grafcet) languages used on automation PLC
PLC Programming Best Practices
Simulador de PLC - lenguaje Ladder
flexmodbus Plugin based HMI interface
Open Source PLC based on the arduino platform