Why link to a fork instead of the main project? https://github.com/tectonic-typesetting/tectonic

That fork is quite curious, it seems like they've really gone out and created quite an active little fork, but haven't spent the time to explain what is different and interesting about their fork in the readme.

The about summarizes it:

> Experimental Oxidization of Tectonic the TeX/LaTeX engine.

...but it's forked from an existing Rust port of Latex.

That's the bit that intrigues me; what is the difference between this port and the original?