This started out as, and for now remains as, a not-very-efficient Mandelbrot Set plotter for the Terminal. It is written in Python, using Textual; written in part as a demonstration but mostly as a really harsh test of the library.
There is a lot about this code that doesn't exactly make it a well-written Textual application; or rather much of it is doing Textual properly, but in some key areas it very much takes a "if you were to do this, don't do it like this" approach. As suggested above, this is on purpose. The code has proven to be, and continues to be, a rather good stress-test of the library.
Eventually, when the sorts of performance issues this code tests are taken care of, I'll likely do a rewrite to make it far more efficient. Until then though, if you're tempted to submit improvements, please don't be offended if I don't accept them -- improvements aren't quite what this code needs right now. ;-)