Original sentence: It is still the most used software suite (in its category) on many operating systems, except for several major GNU/Linux distributions.Until 2006, cdrtools was the standard and most used software suite in its category on GNU/Linux systems as well as on several other operating systems (mainly BSD-based)
Edited sentence: It is still the most used software suite (in its category) on many operating systems, except for several major GNU/Linux distributions which consider the license to be inconsistent and therefore no longer can include cdrtools.Until the licensing change 2006, cdrtools was the standard and most used software suite in its category on GNU/Linux systems as well as on several other operating systems (mainly BSD-based)