PHP was conceived sometime in the fall of 1994 by Rasmus Lerdorf.
Early non-released versions were used on his home page to keep
track of who was looking at his online resume. The first version
used by others was available sometime in early 1995 and was known
as the Personal Home Page Tools. It consisted of a very
simplistic parser engine that only understood a few special macros
and a number of utilities that were in common use on home pages
back then. A guestbook, a counter and some other stuff. The
parser was rewritten in mid-1995 and named PHP/FI Version 2. The
FI came from another package Rasmus had written which interpreted
html form data. He combined the Personal Home Page tools scripts
with the Form Interpreter and added mSQL support and PHP/FI was
born. PHP/FI grew at an amazing pace and people started
contributing code to it.
It is difficult to give any hard statistics, but it is estimated
that by late 1996 PHP/FI was in use on at least 15,000 web sites
around the world. By mid-1997 this number had grown to over
50,000. Mid-1997 also saw a change in the development of PHP. It
changed from being Rasmus' own pet project that a handful of
people had contributed to, to being a much more organized team
effort. The parser was rewritten from scratch by Zeev Suraski and
Andi Gutmans and this new parser formed the basis for PHP Version
3. A lot of the utility code from PHP/FI was ported over to PHP3
and a lot of it was completely rewritten.
Today (end-1999) either PHP/FI or PHP3 ships with a number of
commercial products such as C2's StrongHold web server and RedHat
Linux. A conservative estimate based on an extrapolation from
numbers provided by NetCraft
(see also Netcraft Web Server
Survey) would be that PHP is in use on over 1,000,000
sites around the world. To put that in perspective, that is more
sites than run Netscape's flagship Enterprise server on the
Internet.
Also as of this writing, work is underway on the next generation
of PHP, which will utilize the powerful Zend scripting engine to deliver higher
performance, and will also support running under webservers other
than Apache as a native server module.