Microsoft SQL Server is described as 'SQL Server delivers on Microsoft’s Data Platform vision by helping your organization manage your data by enabling you to store data from structured, semi-structured, and unstructured documents within the database' and is a popular relational database in the development category. There are more than 50 alternatives to Microsoft SQL Server for a variety of platforms, including Windows, Linux, Mac, Web-based and BSD apps. The best Microsoft SQL Server alternative is SQLite, which is both free and Open Source. Other great apps like Microsoft SQL Server are PostgreSQL, MySQL Community Edition, MariaDB and MongoDB.