Blog R&D Why Free Software? 22 September 201522 September 2015 Duduf 0 Comment Duik, Free Software Tough question often asked concerning Duik. Here’s my answer in charts! Comparison of the number and quality of features, the number of users, and the money earned between a free software and a proprietary software. The virtuous circle of the number of users of a free software. The virtuous circle of the features of a free software.