Head Tracking with Cliffs of Dover

[Wolf_Rider]

Its quite possible NP could not, in any way force a developer to lock other products out, if that product utilised gnu items and/ or their own items/ interfacing... NP can, and rightly so, force a developer to lock out anything which takes advantage of NP software, in any form, if they are under product licensing.
Publisher also has a choice of getting involved in the interests of protecting, or not, other softwares copyrights through DRM.