MySQL - The world's most popular open source database
draw.io - Online diagramming application
PostgreSQL - PostgreSQL is a powerful, open source object-relational database system.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Microsoft SQL - Microsoft SQL is a best in class relational database management software that facilitates the database server to provide you a primary function to store and retrieve data.
PlantUML - PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams.