nfsen-ng - nfsen-ng aims to be an in-place replacement for the ageing nfsen.
Ansible - Radically simple configuration-management, application deployment, task-execution, and multi-node orchestration engine
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
FastNetMon - FastNetMon is a very fast DDoS analyzer with sflow/netflow/mirror support.
Puppet Enterprise - Get started with Puppet Enterprise, or upgrade or expand.