On 27 Mar 2025, at 07:18, Demi Marie Obenour via Devel <devel@sel4.systems> wrote: Which is why we’re working on sample designs. LionsOS is a one with a static architecture, that avoids a lot of the complexity (and should ease verification). But we also have a fully dynamic one in the works, but that one is at a very early stage. Will it be possible to implement a POSIX-like API on top of this? By “POSIX-like”, I mean “similar enough to POSIX that existing applications like browsers, web servers, etc can be ported fairly easily.” Having to rely on VMs for anything that isn’t written from scratch for seL4 would not be great. We’re definitely layering an (inherently less efficient, Posix-style) synchronous interface over the asynchronous native API. In fact, that’s already used in your LionsOS-based web server that runs the sel4.systems web site. Others who are closer to the code can provide more details. Gernot