In a nutshell
KC builds on the current ISO C Language Specification to add modern programming paradigms with in-code specified levels of readiness and project-level administration of minimum safety enforcement.
With the compiler built on clang/llvm, the enhancements provide a smooth transition for existing code bases into safer, easy to maintain, and modernized code without forcing a change of the core programming paradigms that have made C the choice of programmers for decades.
KC is not a magic bullet. It does not automatically turn unsafe C code into safe code, but it enhances the C language itself and guides the programmer into transforming old C into KC, so the benefits can be realized, without the costs of changing skill sets and refactoring in other languages.
New projects can be realized in KC as well. KC is intended to be the next ISO C standard, not blazing a trail in a different direction. The goal is to gain all of the benefits of Rust, Zig, and other projects without vastly new syntax, cumbersome bindings, and incompatibilities and within a coding style and simplicity that makes it intuitive and efficient to use for projects from the first line to the last.