I mean this earnestly (no snark): why should I care about T3X? I know that I'm missing the obvious reasons.
You can also use it to bootstrap something more high-level than assembly language in very little time.
I have even written real-life programs in T3X for a while, but I wouldn't recommend it unless you are fascinated by the beauty of typeless languages!
By bootstrapping, I'm referring to building a T3X9 compiler for a new target platform and than using that to create something more interesting. You can start the process by re-implementing the compiler or by re-targeting it.
If you look at the source code, you might learn something.
True, the poster asked specifically about T3X.