The Information Technology Infrastructure Library, ITIL, is a framework of best practices to encourage quality services within the IT sector. It presents a comprehensive set of management procedures for the management of information technology operations.

ITIL emerged in the middle of the 1990's, although it was written originally in the 1980's, and has become the defacto standard for ITSM. It comprises a series of eight books (currently), the subjects of which are known as 'sets'. The sets themselves are sub-divided into 'disciplines', each covering its own defined subject.

The current sets are:
Service Delivery.
Service Support.
Planning to Implement Service Management.
Security Management.
ICT Infrastructure Management.
The Business Perspective.
Application Management.
Software Asset Management.

ITIL also supports a formal training and certification scheme for the individual. Three levels of certification exist:
The ITIL Foundation Certificate
The ITIL Practitioners Certificate
The ITIL Managers Certificate