Software as a service (SaaS; pronounced /sæs/) is a software licensing and delivery model in which software is licensed on a subscription basis and is centrally hosted. It is sometimes referred to as “on-demand software”. SaaS is typically accessed by users using a thin client via a web browser. SaaS has become a common delivery model for many business applications, including office and messaging software, payroll processing software, DBMS software, management software, CAD software, development software, gamification, virtualization, accounting, collaboration, customer relationship management (CRM), management information systems (MIS), enterprise resource planning (ERP), invoicing, human resource management (HRM), talent acquisition, content management (CM), antivirus software, and service desk management. SaaS has been incorporated into the strategy of nearly all leading enterprise software companies.
According to a Gartner Group estimate, SaaS sales in 2010 reached $10 billion and were projected to increase to $12.1 billion in 2011, up 20.7% from 2010.Gartner Group estimates that SaaS revenue will be more than double its 2010 numbers by 2015 and reach a projected $21.3 billion. Customer relationship management (CRM) continues to be the largest market for SaaS. SaaS revenue within the CRM market was forecast to reach $3.8 billion in 2011, up from $3.2 billion in 2010.
The term “software as a service” (SaaS) is considered to be part of the nomenclature of cloud computing, along with infrastructure as a service (IaaS), platform as a service (PaaS), desktop as a service (DaaS), managed software as a service (MSaaS), mobile backend as a service (MBaaS), and information technology management as a service (ITMaaS).
أصبحت البرمجيات كخدمة نموذجاً شائعاً للعديد من تطبيقات الأعمال، بما فيها برمجيات المحاسبة والبرمجيات التعاونية (بالإنجليزية: Collaborative software)، وإدارة علاقات العملاء (CRM)، تخطيط موارد المؤسسات (ERP)، الفواتير (بالإنجليزية: invoicing)، إدارة الموارد البشرية (HRM)، إدارة المحتوى (CM) وإدارة قرص الخدمة .