It is for now, but as both Ladybird and Jakt are SerenityOS projects, eventually parts of Ladybird might get written in Jakt. Jakt compiles to C++ and plans to

It is for now, but as both Ladybird and Jakt are SerenityOS projects, eventually parts of Ladybird might get written in Jakt. Jakt compiles to C++ and plans to have features like "inline C++" to allow easy interop between the two, so I assume they are thinking about this.