Wikipedia:School and university projects/Open Source Culture/GNUProject
GNU is an operating system which uses the kernel Linux and is now widely used. The GNU Project sets forth a new definition of 'free software,' as distinct from 'open source.' The main reason for this distinction is to maintain that free software refers to the liberty of the users, and not necessarily a 'free' price. Thus, users may have acquired the software by either purchasing it or receiving a free copy. In turn, modifiers of the software are allowed to charge or give-away the altered software. So, it is not then necessarily true that free software is indeed costless. In fact, free software only refers to four freedoms:
1. The freedom to run the program. 2. The freedom to study how the program works, and adapt it to your needs. 3. The freedom to redistribute copies so you can help your neighbor. 4. The freedom to improve the program, and release your improvements to the public, so that the whole community benefits.
Thus, the only precondition for the above freedoms to hold is to allow an open source code. However, charging for any GNU product is not a precondition to the above freedomes, and consequently, there need be no stipulations on price. The GNU Project is important in that it explicitly announces a difference between open source and free software. Often open source may be confused with free software. But it must be noted that open source is a step beyond free software.