FLOSS
Free Libre Open Source Software is licensed to allow anybody to change and adjust the source code to make the software run exactly how they need it to run. In many cases, the subsequent changes can be distributed as long as it complies with and includes a copy of the original license. This is sometimes called "CopyLeft" as opposed to Copyrighted software, and is a viable alternative to the proprietary software model, where the source of the product is protected intellectual property and only the original owners or their assigns have a right to edit or modify it. FLOSS is often made available free of charge but that is not the reason Open-source software is also called free software.