There have been several versions of PHP released since its initial release in 1995. Here is a list of some of the major PHP versions:
1. PHP 1 (1995)
2. PHP 2 (1997)
3. PHP 3 (1998)
4. PHP 4 (2000)
5. PHP 5 (2004)
6. PHP 6 (never released)
7. PHP 7 (2015)
8. PHP 8 (2020)
PHP 7 and PHP 8 are considered to be significant updates with performance improvements and new features. PHP 6 was planned to be a major release, but it was abandoned due to technical difficulties and conflicts with the Unicode standard.