Complex sentence: He has since starred in multiple sequels developed by 3D Realms, and most recently in Duke Nukem Forever developed by Gearbox Software, who now own the rights and intellectual property.
Split into simpler sentences: He has since starred in multiple sequels developed by 3D Realms. Most recently, he starred in "Duke Nukem Forever", developed by Gearbox Software, which now own the rights and intellectual property.