A GC lang isn't necessarily significantly slower than C. You should qualify your statements. Moreover, this is a variant of C, which means that the programs are likely less liberal with heap allocations. It remains to be seen how much of a slowdown Fil-C imposes under normal operating conditions. Moreover, although it is indeed primarily suited for existing programs, its use in new programs isn't necessarily worse than, e.g., C# or Go. If performance is the deciding factor, probably use Rust, Zig, Nim, D, etc. .