Antonio,
Do you think mod_harbour is already ready to develop a little app to manage orders ?
Board index mod_harbour New mod_harbour URL
Vilian,
Sure, of course it is ready for that and for much much more 
I really want to do this. For where I must to start ?
Vilian,
Review the mod_harbour samples:
https://www.modharbour.org/modharbour_samples/
https://github.com/FiveTechSoft/mod_harbour/tree/master/samples
Review the mod_harbour samples:
https://www.modharbour.org/modharbour_samples/
https://github.com/FiveTechSoft/mod_harbour/tree/master/samples