Koi fish are ornamental fish.
I've began writing up Twinspark OS' Libk implementation. Anyone who has been into OS Programming knows that their OS needs to be compiled as freestanding i.e. it should not depend on the system's C libraries for much of its functionality. This usually leaves out critical libraries like Stdlib, Stdio etc. So you have to write your own implementations for this.
I've first started with the simpler str* functions to set the ball rolling under Libk.