Yes, now that SDF font rendering is the industry's preference, he drops the software patent. That is, he is dropping the patent because it isn't a commercially viable piece of software, not because he is ethically opposed to it. Great virtue signaling though.

Seems more like he had the patent long enough to build a sustainable business from his own work, and now he’s been able to earn enough from it that others’ implementations aren’t a risk to him.

Which is kind of the entire point of patents, just that they last way too long relative to the speed of technological progress

SDF font rendering was common long before Slug, and Slug is supposed to be the better solution (I haven't used it though, so cannot comment on its pros and cons vs SDF, but one obvious disadvantage of SDF is that you still need a font atlas texture, and that can get very big if you need to render some East Asian character sets).

SDF font rendering has been around 20+ years though? Valve really popularized in their 2007 SIGGRAPH paper and Chlumský developed MSDF font rendering in a 2015 thesis.

SDF font rendering was an industry standard maybe from 2007-2010. and you probably won’t believe what happened to OpenGL since then. Don’t even look into at what people are doing with GPUs these days, you won’t like it one bit!

You do realize he could've just kept it until 2038, right? This was completely unforced.

SDF rendering is just a fuzzy blobby approximation.