Yes, this is a real project that really works. It can compile real and widely used software written in C including SQLite, OpenSSL, and CPython, giving them true memory safety without escape hatches.
From their manifesto [1]: "The biggest impediment to using Fil-C in production is speed. Fil-C is currently about 1.5x-4x slower than legacy C."
And for the moment being it is running only on Linux/X86_64, even though there should be nothing preventing it from running on other platforms.
[1]: https://github.com/pizlonator/llvm-project-deluge/blob/delug...