PHP was originally created and released by Rasmus Lerdorf. Andi Gutmans and Zeev Suraski were the driving force behind the PHP2 -> PHP3 rewrite. The company, Zend Technologies, and the virtual machine powering PHP4+, the Zend Engine, derive their names from Zeev and Andi.
While there's a lot of Zend in PHP, and Rasmus, Andi and Zeev are all involved at various levels, Zend Technologies does not control the development process. Indeed, nobody really controls the development process. php-internals is working on that.
The reason you see Zend all over the place when writing C extensions is due to the Zend Engine.
Zend Framework (ZF) is an open source, object-oriented web application framework implemented in PHP 5 and licensed under the New BSD License.
Zend Technologies, co-founded by PHP core contributors Andi Gutmans and Zeev Suraski, is the corporate sponsor of Zend Framework. Technology partners include IBM, Google,Microsoft,Adobe Systems, and StrikeIron.
Zend Framework features include
- All components are fully object-oriented PHP 5 and are E_STRICT compliant
- Use-at-will architecture with loosely coupled components and minimal interdependencies
- Extensible MVC implementation supporting layouts and PHP-based templates by default
- Support for multiple database systems and vendors, including MariaDB, MySQL, Oracle, IBM DB2, Microsoft SQL Server, PostgreSQL, SQLite, and Informix Dynamic Server
- Email composition and delivery, retrieval via mbox, Maildir, POP3 and IMAP4
- Flexible caching sub-system with support for many types of backends, such as memory or a file system.