Being IT (not a developer) I was always searching for simple easy tune-able and effective solutions. First web server I've managed was IIS 2.0 on Windows NT 4.0 Server. In 1998 it was more than enough for University web page and I was as happy as Larry, and was very proud of my skills thinking that it is rock solid solution for ages
The year 2002 was my graduation, the university admin who replaced me on this post was surprised to see IIS 4.0, and as he said that I had a MustDie! solution. He was the one who showed me Apache, which I hated since my first contact due to I was complete fool in Linux, and continued to use IIS for any tasks in any job places where it was requested until 2005 when I've tasted the power of Linux as a file server and as a proxy server. I was stubbornly continue to use IIS until I've met a demanding PHP developer appeared in the company I work and he almost ate my brain insisting to move company server to APACHE. Yes! that's appeared to be amazing, while I've was quite fluent in Linux and had perfect back server where I've played a lot with apache, and thanks Lance he thought me all he knew about Apache, I've completely abandoned IIS 6.5 and became LAMP guy.
Once I moved to the company, which gives me good salary, but provided tight environment (only 4 quite old servers) with rapidly growing web site which gained from 1 000 000 to 16 000 000 page vies per month in half year, I've realized that I'm f$cked! My idea to deploy a Cluster for $$$$$ was rejected, with friendly reminding about storming job crisis, pushed me for searching a magic-wonder or whatever solution. The site I was responsible for during the peak activity of 3600 concurrent connections made users to wait for page load up to 45 seconds!
I've tried Lighthttpd, ZEUS and finaly in the beginning 2008 I found nginx. I had to learn the new but quite simple syntaxes and bit by bit to collect manuals and solutions how to mange it. First I was using it only for static data proxy, but later on I moved completely to nginx as a standalone web server. Since the 2009 I use nginx for all my customers who request Web Server solution with PHP running projects.
I will try to share all I know about this wonderful product, which has more pros than cons, and hope it will be useful for you.