Hey there, dear interwebs!
Many things happened since I released SONAR back in 2011. I moved to a new city (Berlin), got a real fulltime job, helped the guys from Golden Tricylce on doing the story for their game CLARC and did some kids TV stuff. Now that I have some time to breath, I realized: After Desura went offline some time ago and indievania even a lot earlier, there is no opportunity for you guys to get your hands on SONAR at all! Not good! That's why it's time to finally give it away for free. (Don't mind, I haven't seen any bucks from Desura anyway...)
You'll find the installer in the download section.
P.S.: I'll keep on coding on the sequel now that I'm currently building in Unity3D using a homebrewn voxel system and full VR support. Oh, wait, that's probably worth it's own news article... Well, let's treat it as a rumour until I have time to set up a proper indiedb page for that project.