[miki123211]

I think the core advantage of Fil-C (that Java and C# don't have) is that it moves the decision between security and performance to the user, not the programmer.

Imagine you're writing a library for, let's say, astronomical and orbital calculations. Writing it in Java means that it's always going to be slow. If you write it in C, NASA may decide to compile it with a normal compiler (because it won't ever be exposed to malicious inputs), while an astronomy website operator may use the Fil-C version for the extra security, at the cost of having to use slightly more computing resources, which are abundant on Earth.

This doesn't negate the advantages of Rust, which lets you get speed and performance at the same time.