HeidiSQL

Supports seven major relational databases including MariaDB, PostgreSQL, and SQL Server, as listed in the README, providing a unified interface that eliminates the need for multiple client tools.

Offers a spreadsheet-like view for directly browsing and modifying table data, simplifying common administrative tasks without writing SQL, as highlighted in the key features.

Enables exporting database structure and data to SQL files or transferring between servers, facilitating backups and cross-server migrations, a core feature mentioned in the description.

Licensed as open-source with no cost, making it accessible for professionals and small teams while offering professional-grade functionality compared to paid alternatives.