The first version of PHP, distributed under the name PHP / FI (Personal Home Page / Forms Interpreter), was created by Rasmus Lerdorf in 1994 as a set of Perl scripts used to monitor Internet users visiting the site. When the movement has become too large, he rewrote them in C, adding that the new options. Soon after, people began to ask him about the possibility of using these tools on their sites, so the 8 June 1995 the author of public access to the source code (PHP Tools 1.0). Just a few months later, the project was transformed into a nucleus now known programming language when it was combined with another tool Rasmus Lerdorf - Forms Interpreter, which gave the second part of the name. In 1997, he appeared in PHP / FI 2.0, then having several thousands of active users around the world and the support of 50 thousand. domains. Interestingly, this version had spent most of the "life" on the beta. Official release was only one and was published in November 1997.
In 1997, he became interested in the project, two Israeli programmers: Zeev Suraski and Andi Gutmans. They discovered that PHP / FI is too small for the needs of the application possibilities of eCommerce, which is created at the university. They decided then that prescribe PHP code completely from scratch, with the help of existing PHP community. In June 1998, they announced PHP 3.0 as the successor to PHP / FI, which further development is then stopped. This was a great step forward. PHP 3.0 had a completely new architecture, which significantly increased productivity. They appeared in it the seeds of object-oriented programming, but the most important feature of the application was its modularity. Users could now extend the functionality of the language by adding new modules.
Shortly after the release of PHP 3, in winter 1998 Zeev Suraski and Andi Gutmans again set about rewriting the source code of PHP, using the experience gained in the work on the previous version. Main objectives have chosen to improve the modularity and performance of complex applications. While the previous version could handle them, however, it was not designed for this purpose and by losing it with other solutions.
In mid-1999 was released officially Zend Engine, a new scripting language engine, around which soon after began to build PHP 4. Its name is a compromise combination of the names of the creators of the project. The new, based on the PHP version, it was released in May 2000. As before, it was a huge step forward. Developers now have access to a lot of new tools, language constructs, and more secure input / output system. From the administrative side there was official support for many new servers. For four years from the date of issue they appeared in three consecutive editions of this version numbered 4.1, 4.2 and 4.3. In each of them was felt to increase the safety, speed and performance. In 2004, they served together.