SQL Fiddle : A tool for easy online testing and sharing of database problems and their solutions.
Prettier : Prettier is an opinionated code formatter. It enforces a consistent style by parsing your code and re-printing it with its own rules that take the max...
RoundPic : Online tool for making anti-aliased rounded corners (very Web 2.0!) for avatars and images
Beekeeper Studio : Open Source cross-platform SQL Editor and Database Manager. Use Beekeeper Studio to query and manage your relational databases, like MySQL, Postgres, ...