In 2010, the nginx source was quite startling. It's very readable C, but also somewhat difficult in that it did not mechanize a lot of bookkeeping. If it wanted to construct a string of 8 components, there were 8 components in getting the length right, then 8 adds to the string. This was toil, and error-prone. But it was always done with such precision, and so consistent, that it was still quite beautiful.