Legacy versions prior to 0.5

[etrader]

I've tried most of lightweight web servers, and nginx is truly amazing
and my beloved webserver. Thus, I decided to profoundly study nginx to
better understand it. The oldest version available for download is 0.5

I wonder if there is a repository to download earlier versions of
nginx?

And is there a version working without installation? I mean very basic
version that works just by running nginx in the terminal (I am looking
for a very basic version with least features).

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,219480,219480#msg-219480