All hosts have the latest version of PHP and MariaDB and all of them support .htaccess override. Some hosts even allow custom PHP.INI to further customize settings.
Most of the open-source web applications (and/or closed-source ones) including our free open-source directory script and gallery script require/support the langauge to create your website. Above listed companies have been tested with the most popular scripts on the web. Our scripts (directory, gallery, ip2country, PHP paypal etc) all work flawlessly and fast.
PHP is Web Scripting language originally created by Rasmus Lerdorf in 1995, as Personal Homepage Tools, now referred to as HyperText Preprocessor. After the version 3 release, the language gained popularity and today is one of the most used web programming languages for producing dynamic web sites. The newest version is 7 which adds many features, security, and enhanced OOP (Object Oriented Programming) support. PHP often comes in bundle with Apache httpd - web server and MySQL (now MariaDB) - relational database system, called LAMP or WAMP (L stands for Linux, W for windows). Many popular websites are powered by it including facebook.com, youtube (in the beginning), some google services, digg.com - the news portal and many others. Wordpress the popular weblog (blog) platform is built with PHP.
Shared hosting is subcategory of PHP hosting. It is the most popular type of webhosting service. In this environment everyone is sharing the computer resources (CPU, RAM, disk space and others). Therefore it is cheap and offers tons of features including PHP, MySQL, PostgreSQL, Ruby on Rails on others. You can create blogs, websites, forums (online communities) on a single account. Today almost all providers offer this service. The prices are between $1-$15 / Monthly, and you can host unlimited domains, have unlimited disk space and bandwidth. Technical knowledge is not required at all. The accounts often come with easy to use control panel where you can setup everything you need (including databases, settings, FTP, files/folders, install scripts like wordpress (blog), drupal (content management system - cms), joomla (cms), phpbb (forum software), galleries, shopping carts and other) and other related tasks. The most popular control panel is cPanel, that offers you many features like, file management, backups, one-click installation, addon domains, web statistics etc.