Kamal Hassin, director of technology and product management at open source licence compliance software maker Protecode, said smaller companies which approached his employer for advice on compliance seemed to be more familiar with the GPL and, hence, not half as wary.

The GPL provides four freedoms for any software licensed under it: the freedom to use the software for any purpose, to study and change it, copy and redistribute it, and the freedom to distribute modified versions to all and sundry.

These four freedoms mean that any derivative works of a GPL licensed product will also be under the same licence.

Hassin said the wariness about the GPL was because all the litigation over free and open source software licences had been around the GPL.

Smaller firms had more checks in place compared to big and medium-sized firms which were introducing open source software for the first time.

Hassin said the viral nature of the GPL meant that when people were developing applications for operating systems like Android - which was built atop the Linux kernel but had other bits which were under an Apache licence - they had to be careful about how they went about their task.

Protecode is a private company owned by a few institutional investors and some venture capital firms. It has around 30 full-time staff and a number of contractors on its rolls; the latter handle the legal and licensing aspects and database management.