PLC3000 is an intuitive tool for coding and simulating Programmable Logic Controllers (PLCs) with various interactive scale models. It has the advantage, from the user’s point of view, of using only one page on a web browser. From this web page, the user has access to the exercise topics, to the visualization of the educational scale models, but also to two other sub-windows for programming and debugging, respectively. The code can be written in programming languages Instruction List (IL) or Structured Text (ST) according to IEC 61131 standard. The number of inputs/outputs, memories, timers and counters is not limited. This tool is particularly suitable for the design of Grafcets, their coding, debugging and simulation. It also offers a progression in learning with a wide variety of exercises and interactive scale models.