There is another less known but worth to mention project. There is a man, who wrote highly optimized (literally - he had counted every system call, every buffer

There is another less known but worth to mention project. There is a man, who wrote highly optimized (literally - he had counted every system call, every buffer) web server with proxy functionality - http://nginx.net/ http://nginx.net/ It is another example how one fanatical (and a little paranoid, of course) person could change the world. It is a brilliant work! If you will take a look at its source code - it is like poetry to those who understands. This server is being used mostly on extremely high loaded adult or dating sites around the world. It is also good example of how to do optimizations in general - modify a weakest (a slowest) component, test and measure, change the next one.