Open source doesn't just mean access to the source code. The distribution terms of open-source software must comply with some criteria. Those criterias are Free Distribution, Available Source Code, Work Derivation, Author's Source Code Integrity, No Discrimination Against Persons or Groups, No Discrimination Against Fields of Endeavor, Distribution of License, License Must Not Be Specific to a Product, License Must Not Restrict Other Software, and License Must Be Technology-Neutral.
                                                     -Origin: Bruce Perens; Source: Open Source Initiative

             The advantages of open source software include lower costs; the opportunity for students to learn about programming by examining and modifying the source code; and better reliability than proprietary software.