When Open Firmware Meets Open Vision: A Builder's Note on Polyend and Amblyotube Polyend open-sourcing the Tracker firmware hit Hacker News at 93 points this week. The thread is exactly what you'd expect — developers dissecting MIDI implementations, dreaming up custom sequencers, calculating latency budgets for community forks. I read it on a Thursday evening, Quest 3 on my desk, Amblyotube sideloaded and running a dichoptic session against a YouTube playlist of 80s synth demos. The parallel struck me: both projects bet on the same premise — that the community will build things the original team never imagined. Polyend gave away the Tracker's C++ firmware, HAL drivers, and USB descriptors. We gave away the platform choice — building on Meta Quest's open SDK instead of locking into a $2,000 proprietary goggle ecosystem. Technically, Amblyotube exploits Quest's dual-display pipeline: two independent render passes, one per eye, composited at 72–90 Hz.…