No per-copy fees can be asked for modified versions, and anyone can use the current code base to start new projects. Working knowledge can be gathered at a minimal cost. This is what made Internet software systems such an important factor in the new economy: students, and people trying new technologies were able to integrate and adopt them immediately, without the hurdles of commercial or non-disclosure licence agreements. In addition, the right to freely modify them allowed for the incredible expansion in the number of communication protocols and systems, each perfectly tailored to the needs of their users. This is also a reason for the overwhelming success of the Linux kernel, widely employed by students thanks to its near-zero cost, and subsequently used by the same students in the startups originated by them, when they turn into entrepreneurs after leaving University.