PHP historically did not come with a disposable webserver, and writing one was hard. All the focus was on stateless applications. So while the smart guys were dealing with the memory leaks of their wonderful engineered systems, PHP monkeys were able to get things done with almost no fear to bring down the server.
I remember reading that Aaron Swartz used to go to bed with his laptop in order to be able to quickly restore Reddit in the case it crashed during the night. [Citation needed]
For hosting companies of the time, the choice of the language was pretty obvious. Most of them have policies of automatically killing long-running processes even nowadays.
On that note though, getting mod_wsgi up and running with Apache is really quite simple.
def wsgi_app(environ, start_response):
output = 'Hello World!'
status = '200 OK'
headers = [('Content-type', 'text/plain'),
('Content-Length', str(len(output)))]
start_response(status, headers)
yield output
# mod_wsgi need the *application* variable to serve our small app
application = wsgi_app
<?php
echo 'Hello World!';Adapting your wsgi script for "what? is it in a virtual env? Where? What version of Python is running on this server?" and other similar problems is not so easy.
But yes, it's a matter of an hour or two for a complete newby to complete it. It completely disappears when compared to the time it takes to develop the site, but lots and lots of people consider it the most important aspect of a platform, because it comes first.
If it takes almost no effort to install your language and any modules that users might need, then the system administrator will just add it to the list of things to install. PHP is everywhere because its very easy.