Open source software may sound like just another passing buzz phrase, but it is no fly-by-nighter. It has been around for decades and we have all relied on it for some time. As more and more people are coming into direct contact with open source, it's a good time to ask what makes it so special.
The source here is source code, the human-readable (or at least programmer-readable) form of a computer program.
Computer programs are written in various programming languages (source code) and then translated by computer into instructions a computer can follow directly (machine code). To run the program you only need the machine code. To discover how a program works, or make changes, the source code is essential.
Almost none of the software used by the typical computer user comes with source code. Software giants like Microsoft and Adobe treat source code as a trade secret. After all, the argument goes, these programs are the fruits of their labor; why should they let anyone else study their inner workings? This is closed source, or proprietary, software.
Open source software takes the opposite approach. Not only does the software come with source, but recipients are also allowed to make changes and pass it on to others without charge. The original author gives up the tight control over their source -- and the revenue it could bring them -- in the hope that the software will be enriched even if they are not.
Open source is supposed to encourage better software by allowing more eyes to inspect and correct existing code and providing solid foundations on which new projects can be built. The technical value of opening source up to exploitation by all is supposed to outweigh the monetary value of selling closed copies.
Open source goes back a...

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