That is cool. I had stumbled on that site a few times, but never looked in depth. You don't have to do all the tasks.
Just in that they have sections of tasks and you can add your language to the ones over time that fit.
For example in the 3D task, there are only a few examples. OCaml second version looks neat and clean. TCL, I thought that was a scripting language? Sqlite3 has TCL examples also on their site so it must be popular too. Another language I never really looked at.