Hi Marino,
Answering and commenting some of your questions from the email for the benefit of other users here in the community:
Open Cosmos is producing the qbcan compact for those users who want to focus more on the CanSat payload and software whereas the modular is for users who want also to learn to solder and tinker with electronics at a more hardware level, so the preference depends on the user really.
If you want to try out qbcan compact, you can get it in http://open-cosmos.com/shop/
Answer to your questions:
1- One question, is the software and libraries the same for the modular and the compact kit??
2- Will sketches written for the modular work on the compact???
Libraries are the same, code would be the same with the exception of the pin IDs. The qbcan modular is using the Arduino Pro micro and the pinout might be different to the qbcan compact. So if you asign pin X for a gpio, in the micro it might be a ground pin, just double check for pinouts. Info about pinout for both qbcans is in the wiki: http://doc.open-cosmos.com
Regards,