PostmarketOS is an Alpine Linux based operating system for mobile devices. The postmarketOS blog takes a look at the project after two years of development. "Wouldn't it be great if you could take any obsolete smartphone from the past ten years and replace its outdated and insecure software with a maintained, modular free software stack? How about then using it as a Raspberry Pi-like device for your next tinkering project? With some constraints, postmarketOS makes this possible today for 139 booting devices. Every single package in the whole OS can be updated, with the only exceptions being the vendor's Linux kernel and firmware blobs (if you plan on using them). In a few cases, it is even possible to switch out the discontinued vendor kernel forks with the upstream kernel releases straight from Linus Torvalds."