Why support the POSIX API in Zephyr? We will begin with a brief history of POSIX API support in Zephyr, benefits to the ecosystem, initial contributions, and maintainership. We will explain the differentiation between CONFIG_POSIX_API and CONFIG_ARCH_POSIX and what roles each of those plays in the Zephyr ecosystem and why the two are currently at odds. The current state from the user perspective will follow. What POSIX APIs are supported? This will start from a 10,000 meter view and then zoom in on particular POSIX APIs, explaining why some POSIX APIs are supported and not others. How easy is it to port a POSIX library, samples apps, and testsuite to Zephyr? Believe it or not, it's relatively easy* and there are fairly exact steps to follow. The GSoC 2022 contribution of Apache Thrift will be presented as a case study. Finally, we will look at the LTSv3 roadmap, progress, and proposals, including * Publishing which POSIX embedded profiles are supported * Providing standard feature test macros * Better network API support * Coexistence with POSIX_ARCH * Support for automatic thread stacks * Moving POSIX headers from the toolchain into Zephyr