Code Editors

Sublime Text: offers a free software to edit any language. It is built for PC and Mac, and runs common functions like autocomplete, and tracks all variable names. The editor is also color coded, making differentiations between data types, functions, and objects easy to identify.
Atom: lightweight text editor with a huge package ecosystem and is very customizable.
DataGrip: IDE developed by JetBrains for RDBMSs. Has a large amount of tools for assisting the development of databases, and can support almost any RDBMS flavor, SQL or otherwise.
Vim: The One True Editor. Difficult to learn, harder to master, but once you do, you will have achieved enlightenment and become one with your keyboard.