open source software
Definition:
The noobie way to explain open source software is to think of a software application that has been developed by a user community rather than by a single corporation or entity. Open source software is generally free to use (but doesn't have to be) and the source code used to build the software is freely available for others to download, change or otherwise improve.
One of the most popular open source software applications is OpenOffice, a free, open source competitor to Microsoft's Office suite.
