Open Source software is open in that it is distributed with its source code so that it can be developed as a community project. Teams of programmers work without profit motive on specific open-source projects, including those used in this PEET project---namely Linux (operating system), Apache (Web server), MySQL (database management), PHP (dynamic Web-page builder)---presumably mostly for the joy of programming for the benefit of the community. The software is freely distributed, but this is not technically a requirement of Open Source products; commercial ventures are free to use the software. Users are free to modify the software as their needs demand. Being openly available, products built with open-source software are accessible to anyone world-wide with an appropriate computer.