RTEMS is an RTOS which can run on tons of architectures and processor families within those architectures.
However, the modern Intel x86-64 / AMD64 is not one of the currently
supported architectures.
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Have you ever wanted to try a new operating system for your project, but all the emulators for your target processor support a limited number of features, and you really don’t want to have to test it all on your hardware?
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To be fair, RTEMS does target the i386, but that involves maintaining a lot of legacy code which the community would really rather not do.
This is where my proposal comes in - it targets modern, off-the-shelf hardware, like the x86-64 processors most of us use day-to-day, supporting only the modern non-legacy features (such as UEFI only, not BIOS).
If you want to dig into the nitty-gritty, have a look at my project proposal, and the project page on RTEMS’ Wiki, which will act as an evolving document as the project continues.