Libnodave is a library that provides the necessary functions to connect to and exchange data with Siemens S7 300/400 PLCs (200 family and S5 family now also supported).
Can now also be used under Win32.
Pycontrol lets you control a PLC using libnodave by simply providing CSV files describing the process values read from the PLC. Pycontrol will create a GUI from the CSV files.