It's great that the open source solutions are so strong in this market. It's nice to see nginx carving out a nice bit of market share too.
Another web server project I quite like is Cherokee (http://www.cherokee-project.com/) - it's got a lot of features but still manages to beat Apache, lighthttpd and nginx in a lot of benchmarks. It's got quite a nice web interface to control it too but it's a bit annoying to not have configuration files for automated setups...
+1 for Cherokee. We use it with php5-fpm - it's rock solid, low on memory consumption and super fast. The admin interface rocks. You can edit the config file by hand or by scripts, the file is just not very "human readable".
Another web server project I quite like is Cherokee (http://www.cherokee-project.com/) - it's got a lot of features but still manages to beat Apache, lighthttpd and nginx in a lot of benchmarks. It's got quite a nice web interface to control it too but it's a bit annoying to not have configuration files for automated setups...