U. Bruhin (the primary author of LibrePCB) answered this question on Reddit (https://www.reddit.com/r/PrintedCircuitBoard/comments/9q4j1n/librepcb_first_release

U. Bruhin (the primary author of LibrePCB) answered this question on Reddit (https://www.reddit.com/r/PrintedCircuitBoard/comments/9q4j1n/librepcb_first_release_candidate_is_out_ama/ https://www.reddit.com/r/PrintedCircuitBoard/comments/9q4j1n...): ---Quote:--- Hi! LibrePCB has some very new concepts, especially for library management. You should take a look at my talk at FOSDEM: https://www.youtube.com/watch?v=vu-h5y6tK34 https://www.youtube.com/watch?v=vu-h5y6tK34 (Slides: https://archive.fosdem.org/2018/schedule/event/cad_librepcb/attachments/slides/2267/export/events/attachments/cad_librepcb/slides/2267/librepcb_slides.pdf https://archive.fosdem.org/2018/schedule/event/cad_librepcb/...) As these are extremely different to KiCad's concepts, it would be very difficult to contribute that to KiCad because they need to provide backward compatibility. And KiCad already has a lot of legacy code, so it would become even worse when changing very fundamental concepts. It's very questionable if KiCad developers even would accept such fundamental changes - actually I'm pretty sure that they wouldn't agree with some of LibrePCB's concepts. So the only way was to create a completely new project. And LibrePCB 0.1.0 is only the beginning - I have many more ideas how an EDA tool should look like. With a standalone project I'm much more flexible to implement new features than if every feature would need to be contributed to KiCad.