Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Open source software security is the measure of assurance or guarantee in the freedom from danger and risk inherent to an open source software system.There is an ongoing debate on whether open source software increases software security or is detrimental to its security. There are a variety of different benefits and drawbacks for both sides of the argument. There are also a variety of metrics and models to measure the effectiveness of the security.It is argued that a system is most vulnerable after a potential vulnerability is discovered, but before a patch is created. By measuring the number of days between the vulnerability and when the vulnerability is fixed, a basis can be determined on the security of the system. There are a few caveats to such an approach: not every vulnerability is equally bad, and fixing a lot of bugs quickly might not be better than only finding a few and taking a little bit longer to fix them, taking into account the operating system, or the effectiveness of the fix.