PHP and MySQL are Open Source, meaning that they are free development tools, and there is a large community of dedicated volunteer programmers who contribute to make improvements and are continuously adding features to it. The development tools and database servers that require licensing costs have limited programming resources compared to open source development tools, which have an enormous and fast growing dedicated and knowledgeable community that extends around the world.MySQL is a powerful open source database server built based on a relational database management system (RDBMS) and is capable of handling a large concurrent database connection.
There has been disagreement about which tool is better. Naturally, the developer who is more familiar with one tool over the other will stand behind the tool that he or she has experience with..
One item to note: No matter how great the development tools are that you are developing with, if the application is not developed correctly, the end result may not be worthwhile. PHP and MySQL is built so that anyone with a minimum amount of programming knowledge can put together a browser based web application. This easy entry to PHP development can also create problems when an inexperienced programmer takes on a large Web Application project and does not consider security implications, scalability and the SQL execution time when there are large concurrent connections, just to start.
PHP scripting language is written in C and is powered by the Zend Engine. PHP was originally developed by Rasmus Lerdorf in 1995 and later was rewritten by Zeev Suraski and Andi Gutmans in 1997. Zeev Suraski and Andi Gutmans founded Zend Technology and created the engine behind PHP, the Zend Engine. Suraski and Gutmans have been actively involved in taking PHP to its pinnacle success today.