An open source software solution is one that is freely available to anyone without restriction, and can be modified or improved at will. Open source projects are usually public collaborations in which developers from many countries, companies, and backgrounds work together to develop parts of the program. These projects are typified by rapid prototyping, open exchange of ideas, transparency, and community-oriented development.
Open source software licenses are often called copyleft licenses. In contrast with the traditional copyright approach, which aggressively protects the exclusive rights of the creator/owner of the source code, a copyleft license grants users permission to use, distribute, and modify open source software however they want to without cost. The only stipulation is that when they release their modified version, they have to release the source code with it.
Users benefit greatly from this approach to software development and distribution. Programmers find that it gives them more control than proprietary software, so they can make improvements that will cause the software to work better for them. Many people consider open source software more secure, and generally of higher quality, because it is being worked on simultaneously by so many programmers, so the chances are greater that errors will be caught and fixed. It also saves individuals and organizations a lot of money every year, and the fact that it uses open standards rather than proprietary standards means that it effectively prevents vendor lock-in.
One of the most successful examples of open source software is the Linux OS and its derivative Android OS for mobile devices. The Android, a mobile OS developed by Google based on the Linux kernel, was designed for touchscreen devices like smartphones and is now being used in cars, wearables, game consoles, cars, and much more. Android is currently the most popular operating system in the world.