Icinga is an open source computer system and network monitoring application. Icinga is attempting to get past perceived short-comings in Nagios' development process, as well as adding new features such as a modern Web 2.0 style user interface, additional database connectors (for MySQL, Oracle, and PostgreSQL), and a REST API that lets administrators integrate numerous extensions without complicated modification of the Icinga core.

The Icinga developers also seek to reflect community needs more closely and to integrate patches more quickly.

Icinga offers Nagios’ features with some additions such as optional reporting module with improved SLA accuracy, additional database connectors for PostgreSQL and Oracle, and distributed systems for redundant monitoring.

lcinga also maintains configuration and plug-in compatibility with Nagios, facilitating migration between the two monitoring software.