First steps

A typical SPP session follows the same five steps, whether you are writing a new configuration or just running one that already exists.

Pick a configuration.
A configuration file (.spp) describes one machine/controller: kinematics, number formats, address codes, G/M codes and the Pascal script that turns APT commands into output. Pick one from the Configurations menu (or Configurations → Load), then adjust it if needed from the Script settings tab. The supplied configurations cover Fanuc, Siemens Sinumerik, Heidenhain TNC, Haas, Mitsubishi, Hurco, ECS and Selca controls.
Load an APT/CL file.
Use File → Load APT/CL file (Ctrl+O) to load the cutter-location file exported by your CAM system. SPP reads it and lists every APT_* function your script defines for it in the function list on the left.
Review the script.
The Script panel shows the Pascal script tied to the current configuration. Each APT command (GOTO, CYCLE, SPINDL, FEDRAT...) is handled by the matching APT_<command> function, if your script defines one.
Run it.
Script → Run (F9) compiles and executes the script against the loaded APT/CL file. The supplied configurations first show an options dialog: below Select machine type the options are grouped in the General (retractions, tools, codes, blocks), Advanced (program start/end, brakes) and Split tabs; in Split, Sub-programs (No / Each tool / Each operation) writes one sub-program per tool or per operation, in the same file as the main program (Sub-programs in the same file) or in separate files next to it. The output panel fills with the resulting G-code as it is generated.
Check the result.
The Log tab reports whether the run succeeded, together with the configuration, input and output file paths, the number of lines produced and the time it took. If something needs fixing, set a breakpoint and use the script debugger to step through the conversion line by line.

Once a configuration is finished, the same conversion can be triggered without opening the UI at all — see Batch mode.