"The functions performed by a computer program depend on its 'source code' ('code'). The code is an integral part of a computer program and is, therefore, heavily protected. He who possesses the code controls the software, and thus software companies spend fortunes trying to protect the code, so as to restrict other programmers from modifying such software, which would otherwise decrease the economic value of the software. Such software, wherein users/licensees do not have access to the code, is referred to as 'closed source software.' Owners of such software rely on the protection afforded by intellectual property statutes for protection of the same..."
Complete Story[Note: This article now requires free registration. It did not when it was originally located. Apologies. -BKP]