The difference is that nginx really works. I had Panoramio, a photo website featured in Google Earth / Maps, using Apache. It started to fail down under load, and I quickly switched to lighttpd. It was faster but crashing, getting OOM, etc. I fixed a memory leak and a few more bugs, but it still crashed every now and then and I looked for alternatives.

This was 2006 and nginx was the only realistic alternative on the market. It worked beautifully since day 1. It saved my startup. Next year we got acquired by Google.

I only got 1 crash with nginx and it was partially my fault, I had an "expires 30y" on some images, and a morning on feb 2008 I came to the office and the whole site was down. After a very quick gdb session under panic I realized it was trying to get a weekday name on an array with a negative index. Nginx was adding 30 years to the current date and that was over 2038 and it overflowed. Igor fixed that issue in hours, and he graciously explained that I could have used "expires max"

Nginx has powered all my startups since then (Freepik, Flaticon, Slidesgo, Besoccer).

This guy has added more real value to the economy than most unicorns. A true hero.