PHP

A little bit of history

Once upon a time, PHP was developed as a means to track visitors to Rasmus Lerdorf's online resume. It consisted of a bunch of perl scripts which Rasmus referred to as "Personal Home Page / Forms Interpreter", or PHP/FI in short. As Rasmus' needs grew, he built an implementation of his tools in c, which would eventually be released as PHP/FI 2.0 in november of 1997, at which time it was estimated to be installed on 1% or less of all the servers on the internet.

In 1997, two university students;  Andi Gutmans and Zeev Suraski teamed up with Rasmus to develop what would become PHP 3, a complete rewrite and with a very extensible architecture. The community now had access to many different databases and interfaces with tools like ImageMafgick. Many developers joined the effort and many extensions to PHP were produced. PHP 3 was also the first php that had some object oriented features, but they were sort of tacked on and not really at the core of the language.

Not too long after the release of PHP 3, PHP 4 was released. it was in 1998 that we got a semi decent object model. PHP was pretty popular by now, but the real kickoff in my eyes came in 2004 with the release of PHP 5, where finally the object model was pretty mature and very usable.

source: My own experience and php.net

Popular misconceptions

There are a lot of things people say about PHP that are just plain not true, I'll name a few here.

PHP sucks

Many people think PHP sucks. I tend to believe these people haven't really used PHP, or just have something against dynamic languages in general. PHP most definitely does not suck. It's not always the right tool for the job, but It powers some of the worlds most popular websites. 

PHP doesn't scale

Scaling well isn't up to the language but the application architect and developer(s). Facebook is powered by PHP and you can't tell me it doesn't gracefully handle a bazillion users concurrently.

PHP is insecure

Like scalability, security is not in the hands of the language but the developer

PHP isn't object oriented

Yes it is, it might be missing some neat features, but there is a pretty decent OO system built right into PHP, it has out of the box support for abstract classes, interfaces, type hinting, inheritance, and many more features.