Database Tools

ODBC Driver for SQL Server
Free
MySQL Community Server
Free
The freely downloadable version of the world's most popular open source database.
Microsoft SQL Server Express
Free
A powerful and reliable free data management system.
PostgreSQL
Free
A powerful, open source object-relational database system.
Oracle Database Express Edition
Free
A free edition of Oracle Database.
SQLite
Free
An in-process library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine.
H2 Database Engine
Free
H2 is free SQL database written in Java.
MariaDB Server
Free
The open source relational database.
DAX Studio
Free
The ultimate tool for working with DAX Queries.
Jailer
Free (Open Source)
Database Subsetting and Relational Data Browsing Tool.
dbForge Event Profiler for SQL Server
Free
Collect and Analyze SQL Server Trace Data.