The first web server was the NCSA httpd. It was small, simple and had a lot of room for improvement, but it was open source and available by FTP, so lots of people made individual improvements. There were no public source repositories and no binary distributions, so these patches got around by email following grass roots discussion in Usenet and other places. NCSA didn't collect or distribute patches, so every site ran a different version of the code, depending on which patches had been applied
Then NCSA announced new licence conditions, restricting open source rights. Something had to be done. A group of people decided to collect and test and merge all the patches they could get. "A patchy webserver" was born... better known as "Apache webserver". And the rest is history.