2. QUALITYCHARACTERISTICSINOSS
Software quality is one of the most important metrics for the success of a software project. Barry Boehm defines software quality as “ achieving high levels of user satisfaction, portability, maintainability, robustness and fitness for use” [10]. Jones refers to quality as “ the absence of defects that would make software either stop completely or produce unacceptable results” [11]. These definitions of software quality cannot be applied directly to OSS. Unlike CSS, user requirements are not formally available in OSS. Existing quality models provide a list of quality carrying characteristics that are responsible for high quality (or otherwise) of software. We can divide OSS into two major categories: Type- 1: Projects that are developed to replicate and replace existing CSS software; and Type-2: Projects initiated to create new software that has no existing equivalent CSS software. Linux is an example of Type-1 software, which was originally developed as a replacement for UNIX. Protégé, ontology development software is an example of Type-2 software. We identify some important quality carrying characteristics in OSS.