What database management systems have you worked with in practice?

In PHP practice, the following database management systems (DBMS) are often used:

• MySQL / MariaDB — the most popular relational DBMS, widely used with PHP due to support for the mysqli extension and PDO.
• PostgreSQL — a powerful relational DBMS with advanced features, also supported via PDO.
• SQLite — an embedded lightweight DBMS, convenient for small projects and testing.
• MongoDB — a document-oriented NoSQL database, often used with PHP through drivers and ODM (e.g., Doctrine MongoDB).

Depending on the task and project requirements, the choice of DBMS may vary, but the above are the most common in PHP development.