I don’t think Fil-C supplants Rust; Rust still has a place for things like kernel development where Fil-C would not be accepted since it wouldn’t work there. But also Rust today has significantly better performance and memory usage so makes more sense for greenfield projects that might otherwise consider C/C++. Not to mention that Rust as a language is drastically easier and faster to develop in due to a modern package management system, a good fast cohesive std library, true cross platform support, static catching of all the issues that would otherwise cause Fil-C to crash instead in addition to having better performance without effort.

Fil-C is an important tool to secure traditional software but it doesn’t yet compete with Rust in the places it’s competing with C and C++ in greenfield projects (and it may never - that’s ok - it’s still valuable to have a way to secure existing code without rewriting it).

And I disagree with the characterization of Graydon’s blog. It’s literally praising Fil-C and saying it’s a valuable piece of tech in the landscape of language dev and worth paying attention to as a serious way to secure a huge amount of existing code. The only position Graydon takes is that safety is a critically important quality of software and Fil-C is potentially an important part of the story of moving the industry forward.