BookWidgets - BookWidgets is an excellent application that let you create engaging exercises in minutes and easily share a varied variety of beautiful and fun activities with your classroom and others.
MySQL - The world's most popular open source database
Padlet - Visual boards for organizing anything.
PostgreSQL - PostgreSQL is a powerful, open source object-relational database system.
Quizlet - Quizlet allows you to review and create flashcards for a variety of subjects, such as math and reading.
SQLite - SQLite Home Page