**A curated list of amazingly awesome Free and Open-Source sysadmin resources.** Please read the [Pull Request template](./.github/PULL_REQUEST_TEMPLATE.md) if you wish to add software and consider [donating](https://github.com/n1trux/awesome-donations) to the FLOSS projects you use regularly. Please consider contributing to fix one of the pinned [issues](https://github.com/awesome-foss/awesome-sysadmin/issues) if your time allows.
- [Apache Ant](https://ant.apache.org/) - Automation build tool, similar to make, a library and command-line tool whose mission is to drive processes described in build files as targets and extension points dependent upon each other. ([Source Code](https://github.com/apache/ant)) `Apache-2.0``Java`
- [Apache Maven](http://maven.apache.org/) - Build automation tool mainly for Java. A software project management and comprehension tool. Based on the concept of a project object model (POM), Maven can manage a project's build, reporting and documentation from a central piece of information. ([Source Code](https://github.com/apache/maven)) `Apache-2.0``Java`
- [Bazel](http://www.bazel.io/) - A fast, scalable, multi-language and extensible build system. Used by Google. ([Source Code](https://github.com/bazelbuild/bazel/)) `Apache-2.0``Java`
- [Bolt](https://puppet.com/products/bolt) - You can use Bolt to run one-off tasks, scripts to automate the provisioning and management of some nodes, you can use Bolt to move a step beyond scripts, and make them shareable. ([Source Code](https://github.com/puppetlabs/bolt)) `Apache-2.0``Ruby`
- [GNU Make](http://www.gnu.org/software/make/) - The most popular automation build tool for many purposes, make is a tool which controls the generation of executables and other non-source files of a program from the program's source files. ([Source Code](https://git.savannah.gnu.org/cgit/make.git)) `GPL-3.0``C`
- [Gradle](http://gradle.org/) - Another build automation system. ([Source Code](https://github.com/gradle/gradle)) `Groovy/Java``Apache-2.0`
- [Rake](https://ruby.github.io/rake/) - Build automation tool similar to Make, written in and extensible in Ruby. ([Source Code](https://github.com/ruby/rake)) `MIT``Ruby`
- [Dar](http://dar.linux.free.fr/) - Which stands for Disk ARchive, is a robust and rich featured archiving and backup software of the tar style. ([Source Code](https://github.com/Edrusb/DAR)) `GPL-2.0``C++`
- [Proxmox Backup Server](https://www.proxmox.com/en/proxmox-backup-server) - Proxmox Backup Server is an enterprise-class, client-server backup solution thatis capable of backing up virtual machines, containers, and physical hosts. ([Source Code](https://www.proxmox.com/en/downloads/category/isoimages-pbs)) `GPL-3.0``Rust`
- [EasyBuild](https://easybuild.readthedocs.org/en/latest/) - EasyBuild builds software and modulefiles for High Performance Computing (HPC) systems in an efficient way.
- [environment-modules Lmod](https://www.tacc.utexas.edu/research-development/tacc-projects/lmod) - Lmod is a Lua based module system that easily handles the MODULEPATH Hierarchical problem.
- [HPCBIOS](http://hpcbios.readthedocs.org/en/latest/) - HPCBIOS is an effort to setup a common, well-documented and reproducible, environment spanning across multiple HPC systems & sites, *inclusive* of documentation.
- [Spack](https://spack.io/) - A flexible package manager that supports multiple versions, configurations, platforms, and compilers.
- [Eggdrop](http://www.eggheads.org/) - The oldest Internet Relay Chat (IRC) bot still in active development. ([Source Code](https://github.com/eggheads/eggdrop)) `GPL-2.0``C`
- [Errbot](http://errbot.io/) - a plugin based chatbot designed to be easily deployable, extensible and maintainable. ([Source Code](https://github.com/errbotio/errbot)) `GPL-3.0``Python`
- [Cobbler](http://cobbler.github.io/) - Cobbler is a Linux installation server that allows for rapid setup of network installation environments. ([Source Code](https://github.com/cobbler/cobbler))
- [BOSH](http://bosh.io/docs/) - IaaS orchestration platform originally written for deploying and managing Cloud Foundry PaaS, but also useful for general purpose distributed systems.
- [Cloud Foundry](https://www.cloudfoundry.org/) - A Platform-as-a-Service suite to provide the orchestration services that make distributed apps a powerhouse of awesomeness.
- [Cloudify](http://getcloudify.org/) - TOSCA-based cloud orchestration software platform written in Python and YAML.
- [CloudSlang](http://www.cloudslang.io/) - Flow-based orchestration tool for managing deployed applications, with Docker capabilities.
- [Genesis](https://github.com/starkandwayne/genesis) - A template framework for multi-environment BOSH deployments.
- [Juju](https://jujucharms.com/) - Cloud orchestration tool which manages services as charms, YAML configuration and deployment script bundles.
- [Kubernetes](http://kubernetes.io/) - Orchestration system for Docker containers - ([Source Code](https://github.com/kubernetes/kubernetes), [Documentation](http://kubernetes.io/docs/)) `Apache-2.0``Go`
- [MCollective](https://puppet.com/mcollective) - Ruby framework to manage server orchestration, developed by Puppet labs.
- [Nomad](https://www.nomadproject.io) - Simple and flexible orchestrator for Docker, Podman, executables, Java, and QEMU - ([Source Code](https://github.com/hashicorp/nomad), [Documentation](https://www.nomadproject.io/docs)) `MPL-2.0``Go`
- [Overcast](http://andrewchilds.github.io/overcast/) - Deploy VMs across different cloud providers, and run commands and scripts across any or all of them in parallel via SSH.
- [Salt](http://saltstack.com/) - Fast, scalable and flexible systems management software written in Python/ZeroMQ.
- [Spruce](https://github.com/geofffranks/spruce) - A tool that merges separate YAML files into one. Works well with [Genesis](https://github.com/starkandwayne/genesis).
- [StackStorm](https://stackstorm.com/) - Event Driven Operations and ChatOps platform for infrastructure management. Written in Python.
- [Terraform](https://www.terraform.io/) - Terraform works with many cloud providers and creates infrastructure from code.
- [Concourse](https://concourse-ci.org/) - Concourse is a CI tool that treats pipelines as first class objects and containerizes every step along the way. ([Demo](https://ci.concourse-ci.org/), [Source Code](https://github.com/concourse/concourse)) `Apache-2.0``Go`
- [drone](https://drone.io/) - Drone is a Continuous Delivery platform built on Docker, written in Go. ([Source Code](https://github.com/drone/drone)) `Apache-2.0``Go`
- [Factor](http://www.factor.io/) - Programmatically define and run workflows to connect configuration management, source code management, build, continuous integration, continuous deployment and communication tools. ([Source Code](https://github.com/factor-io/factor)) `MIT``Ruby`
- [GolangCI](https://golangci.com/) - Open Source automated code review service for Go integrated with GitHub pull requests. ([Source Code](https://github.com/golangci/golangci)) `AGPL-3.0``Go`
- [PHP Censor](https://github.com/php-censor/php-censor) - Open source self-hosted continuous integration server for PHP projects. `BSD-2-Clause``PHP`
- [PHPCI](https://www.phptesting.org/) - Free and open source continuous integration specifically designed for PHP. ([Source Code](https://github.com/block8/phpci)) `BSD-2-Clause``PHP`
- [werf](https://werf.io/) - Open Source CI/CD tool for building Docker images and deploying to Kubernetes via GitOps. ([Source Code](https://github.com/werf/werf)) `Apache-2.0``Go`
- [Woodpecker](https://woodpecker-ci.org/) - Community fork of Drone that uses Docker containers. ([Source Code](https://github.com/woodpecker-ci/woodpecker)) `Apache-2.0``Go`
- [Froxlor](https://froxlor.org/) - Lightweight server management software with Nginx and PHP-FPM support. ([Source Code](https://github.com/Froxlor/Froxlor/)) `GPL-2.0``PHP`
- [ISPConfig](http://www.ispconfig.org) - Manage Linux servers directly through your browser. ([Source Code](https://git.ispconfig.org/ispconfig/ispconfig3)) `BSD-3-Clause``PHP`
- [Sentora](http://sentora.org/) - Open-Source Web hosting control panel for Linux, BSD (fork of ZPanel). ([Source Code](https://github.com/sentora/sentora-core)) `GPL-3.0``PHP`
- [VestaCP](http://vestacp.com/) - Open-Source hosting control panel. ([Source Code](https://github.com/serghey-rodin/vesta)) `GPL-3.0``PHP/Shell/Other`
- [Virtualmin](http://www.virtualmin.com/) - Powerful and flexible web hosting control panel for Linux and BSD systems. ([Source Code](https://github.com/virtualmin)) `GPL-3.0``Shell/Perl/Other`
- [Webmin](http://www.webmin.com/) - Web-based interface for system administration for Unix. ([Source Code](https://github.com/webmin/webmin)) `BSD-3-Clause``Perl`
- [Capistrano](http://capistranorb.com/) - Deploy your application to any number of machines simultaneously, in sequence or as a rolling set via SSH (rake based).
- [Fabric](http://www.fabfile.org/) - Python library and cli tool for streamlining the use of SSH for application deployment or systems administration tasks.
- [Mina](http://nadarei.co/mina/) - Really fast deployer and server automation tool (rake based).
- [munki](https://www.munki.org/munki/) - Webserver-based repository of packages and package metadata, that allows macOS administrators to manage software installs.
- [Vlad the Deployer](https://github.com/seattlerb/vlad) - Deployment automation (rake based).
- [DrawThe.Net](http://go.drawthe.net/) - Javascript tool that uses a YAML-formatted input to programmatically create large, complex, and visually solid diagrams.
- [Mermaid](https://mermaid-js.github.io/mermaid-live-editor/) - Javascript module with a unique, easy, shorthand syntax. Integrates into several other tools like Grafana.
- [DRBD](https://linbit.com/drbd/) - Distributed replicated storage system, implemented as a Linux kernel driver. ([Source Code](https://github.com/LINBIT/drbd)) `GPL-2.0``C`
- [GlusterFS](https://www.gluster.org/) - Software-defined distributed storage that can scale to several petabytes, with interfaces for object, block and file storage. ([Source Code](https://github.com/gluster/glusterfs)) `GPL-2.0/LGPL-3.0``C`
- [Hadoop Distributed Filesystem (HDFS)](https://hadoop.apache.org/) - Distributed file system that provides high-throughput access to application data. ([Source Code](https://github.com/apache/hadoop)) `Apache-2.0``Java`
- [JuiceFS](https://juicefs.com/) - Distributed POSIX file system built on top of Redis and S3. ([Source Code](https://github.com/juicedata/juicefs)) `Apache-2.0``Go`
- [Kubo](https://github.com/ipfs/kubo) - Implementation of IPFS, a global, versioned, peer-to-peer filesystem that seeks to connect all computing devices with the same system of files. `Apache-2.0/MIT``Go`
- [Minio](https://min.io/) - High-performance, S3 compatible object store built for large scale AI/ML, data lake and database workloads. ([Source Code](https://github.com/minio/minio)) `AGPL-3.0``Go`
- [Perkeep](https://perkeep.org/) - A set of open source formats, protocols, and software for modeling, storing, searching, sharing and synchronizing data (previously Camlistore). ([Source Code](https://github.com/perkeep/perkeep)) `Apache-2.0``C`
- [TahoeLAFS](https://tahoe-lafs.org/trac/tahoe-lafs) - Secure, decentralized, fault-tolerant, peer-to-peer distributed data store and distributed file system. ([Source Code](https://github.com/tahoe-lafs/tahoe-lafs)) `GPL-2.0``Python`
- [XtreemFS](https://www.xtreemfs.org/) - Distributed, replicated and fault-tolerant file system for federated IT infrastructures.. ([Source Code](https://github.com/xtreemfs/xtreemfs)) `BSD-3-Clause``Java`
- [Bind](https://www.isc.org/bind/) - Versatile, classic, complete name server software. ([Source Code](https://gitlab.isc.org/isc-projects/bind9)) `MPL-2.0``C`
- [CoreDNS](https://coredns.io/) - Flexible DNS server. ([Source Code](https://github.com/coredns/coredns)) `Apache-2.0``Go`
- [djbdns](http://cr.yp.to/djbdns.html) - A collection of DNS applications, including tinydns. ([Source Code](https://salsa.debian.org/debian/djbdns)) `Public Domain``C`
- [dnsmasq](https://www.thekelleys.org.uk/dnsmasq/doc.html) - Provides network infrastructure for small networks: DNS, DHCP, router advertisement and network boot. ([Source Code](https://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=tree)) `GPL-2.0``C`
- [Knot](https://www.knot-dns.cz/) - High performance authoritative-only DNS server. ([Source Code](https://gitlab.nic.cz/knot/knot-dns)) `GPL-3.0``C`
- [NSD](https://www.nlnetlabs.nl/projects/nsd/about/) - Authoritative DNS name server developed speed, reliability, stability and security. ([Source Code](https://github.com/NLnetLabs/nsd)) `BSD-3-Clause``C`
- [PowerDNS Authoritative Server](https://doc.powerdns.com/authoritative/) - Versatile nameserver which supports a large number of backends.. ([Source Code](https://github.com/PowerDNS/pdns)) `GPL-2.0``C++`
- [Unbound](https://nlnetlabs.nl/projects/unbound/about/) - Validating, recursive, and caching DNS resolver. ([Source Code](https://github.com/NLnetLabs/unbound)) `BSD-3-Clause``C`
- [Yadifa](https://www.yadifa.eu/) - Clean, small, light and RFC-compliant name server implementation developed from scratch by .eu. ([Source Code](https://github.com/yadifa/yadifa)) `BSD-3-Clause``C`
- [Pi-hole](https://pi-hole.net/) - A blackhole for Internet qdvertisements with a GUI for management and monitoring. ([Source Code](https://github.com/pi-hole/pi-hole)) `EUPL-1.2``Shell/PHP`
- [Poweradmin](https://www.poweradmin.org/) - Web-based DNS control panel for PowerDNS server. ([Source Code](https://github.com/poweradmin/poweradmin)) `GPL-3.0``PHP`
- [DNSControl](https://stackexchange.github.io/dnscontrol/) - Synchronize your DNS to multiple providers from a simple DSL. ([Source Code](https://github.com/StackExchange/dnscontrol)) `MIT``Go/Docker`
- [DomainMOD](https://domainmod.org) - Manage your domains and other internet assets in a central location. ([Source Code](https://github.com/domainmod/domainmod.git)) `GPL-3.0``PHP`
- [Notepad++](https://notepad-plus-plus.org/) - GPLv2 multi-language editor with syntax highlighting for Windows.
- [TextMate](https://github.com/textmate/textmate/) - A graphical text editor for OS X.
- [Vim](http://www.vim.org) - A highly configurable text editor built to enable efficient editing.
- [VSCodium](https://github.com/VSCodium/vscodium) - An open source cross-platform extensible code editor based on [VS Code by Microsoft](https://code.visualstudio.com/) removing their non-free additions.
- [389 Directory Server](https://www.port389.org/) - Enterprise-class Open Source LDAP server for Linux. ([Source Code](https://github.com/389ds/389-ds-base)) `GPL-3.0``C`
- [Apache Directory Server](https://directory.apache.org/apacheds/) - Extensible and embeddable directory server, certified LDAPv3 compatible, with Kerberos 5 and Change Password Protocol support, triggers, stored procedures, queues and views. ([Source Code](https://github.com/apache/directory-server)) `Apache-2.0``Java`
- [FreeIPA](https://www.freeipa.org/) - Integrated security information management solution combining Linux (Fedora), 389 Directory Server, Kerberos, NTP, DNS, and Dogtag Certificate System (web interface and command-line administration tools). ([Source Code](https://pagure.io/freeipa)) `GPL-3.0``Python/C/JavaScript`
- [FreeRADIUS](https://freeradius.org/) - Multi-protocol policy server (radiusd) that implements RADIUS, DHCP, BFD, and ARP and associated client/PAM library/Apache module. ([Source Code](https://github.com/FreeRADIUS/freeradius-server)) `GPL-2.0``C`
- [lldap](https://github.com/nitnelave/lldap) - Light (simplified) LDAP implementation with a simple, intuitive web interface and GraphQL support. `GPL-3.0``Rust`
- [OpenID Connect](http://openid.net/developers/libraries/) - A Simple Identity layer on top of OAuth 2.0.
- [OSIAM](http://osiam.github.io/) - Secure identity management solution providing REST based services for authentication and authorization.
- [Pomerium](https://www.pomerium.io/) - An identity and context aware access-proxy inspired by BeyondCorp.
- [Samba](https://www.samba.org/) – Active Directory and CIFS protocol implementation.
- [Smallstep Certificates](https://smallstep.com/certificates/) - A private certificate authority (X.509 & SSH) and related tools for secure automated certificate management.
- [ZITADEL](https://github.com/caos/zitadel) - Cloud-native Identity & Access Management solution providing a platform for secure authentication, authorization and identity management.
- [Authelia](https://www.authelia.com/) - The Single Sign-On Multi-Factor portal for web apps. ([Source Code](https://github.com/authelia/authelia)) `Apache-2.0``Go`
- [GLPI](https://www.glpi-project.org/) - Information Resource-Manager with an additional Administration Interface. ([Source Code](https://github.com/glpi-project/glpi))
- [OCS Inventory NG](https://ocsinventory-ng.org/) - Asset management and deployment solution for all devices in your IT Department. ([Source Code](https://github.com/OCSInventory-NG)) `GPL-2.0``PHP/Perl`
- [OPSI](http://www.opsi.org) - Hardware and software inventory, client management, deployment, and patching for Linux and Windows. ([Source Code](https://github.com/opsi-org/)) `GPL-3.0/AGPL-3.0``OVF/Python`
- [RackTables](http://racktables.org/) - Datacenter and server room asset management like document hardware assets, network addresses, space in racks, networks configuration. ([Source Code](https://github.com/RackTables/racktables), [Demo](https://www.racktables.org/demo.php)) `GPL-2.0``PHP`
- [Ralph](https://ralph.allegro.tech/) - Asset management, DCIM and CMDB system for large Data Centers as well as smaller LAN networks. ([Source Code](https://github.com/allegro/ralph), [Demo](https://github.com/allegro/ralph#live-demo)) `Apache-2.0``Python/Docker`
- [Fluentd](https://www.fluentd.org/) - Data collector for unified logging layer. ([Source Code](https://github.com/fluent/fluentd)) `Apache-2.0``Ruby`
- [Flume](https://flume.apache.org/) - distributed, reliable, and available service for efficiently collecting, aggregating, and moving large amounts of log data. ([Source Code](https://github.com/apache/flume)) `Apache-2.0``Java`
- [GoAccess](https://goaccess.io/) - Real-time web log analyzer and interactive viewer that runs in a terminal or through the browser. ([Source Code](https://github.com/allinurl/goaccess)) `MIT``C`
- [Loki](https://grafana.com/oss/loki/) - Log aggregation system designed to store and query logs from all your applications and infrastructure. ([Source Code](https://github.com/grafana/loki)) `AGPL-3.0``Go`
- [Claws Mail](http://www.claws-mail.org/) - Old school email client (and news reader), based on GTK+. ([Source Code](https://git.claws-mail.org/?p=claws.git;a=tree))
- [ImapSync](http://imapsync.lamiral.info/) – Simple IMAP migration tool for copying mailboxes to other servers. ([Source Code](https://github.com/imapsync/imapsync))
- [Sylpheed](http://sylpheed.sraoss.jp/en/) – Still developed predecessor to Claws Mail, lightweight mail client. ([Source Code](https://github.com/sylpheed-mail/sylpheed))
- [Thunderbird](https://www.thunderbird.net/) - Free email application that's easy to set up and customize. ([Source Code](https://hg.mozilla.org/comm-central/file))
- [Adagios](http://adagios.org/) - Web based Nagios interface for configuration and monitoring (replacement to the standard interface), and a REST interface. ([Source Code](https://github.com/opinkerfi/adagios)) `AGPL-3.0``Docker/Python`
- [Bloonix](https://bloonix-monitoring.org/) - Bloonix is a monitoring solution that helps businesses to ensure high availability and performance. ([Source Code](https://github.com/bloonix)) `GPL-3.0``Perl`
- [cadvisor](https://github.com/google/cadvisor) - Analyzes resource usage and performance characteristics of running containers ([Source Code](https://github.com/google/cadvisor)) `Apache-2.0``Go`
- [checkmk](https://checkmk.com/) - Comprehensive solution for monitoring of applications, servers, and networks. ([Source Code](https://github.com/tribe29/checkmk)) `Python/PHP`
- [dashdot](https://github.com/MauriceNino/dashdot) - A simple, modern server dashboard for smaller private servers. ([Demo](https://dash.mauz.io)) `MIT``Nodejs/Docker`
- [EdMon](https://github.com/Edraens/EdMon) - A command-line monitoring application helping you to check that your hosts and services are available, with notifications support. `MIT``Java`
- [eZ Server Monitor](http://www.ezservermonitor.com) - A lightweight and simple dashboard monitor for Linux, available in Web and Bash application. ([Source Code](https://github.com/shevabam/ezservermonitor-web)) `GPL-3.0``PHP/Shell`
- [Icinga](https://www.icinga.com/) - Nagios fork that has since lapped nagios several times. Comes with the possibility of clustered monitoring. ([Source Code](https://github.com/Icinga/icinga2)) `GPL-2.0``C++`
- [LibreNMS](http://www.librenms.org) - Fully featured network monitoring system that provides a wealth of features and device support. ([Source Code](https://github.com/librenms/librenms)) `GPL-3.0``PHP`
- [Monit](http://mmonit.com/monit/#home) - Small utility for managing and monitoring Unix systems. ([Source Code](https://bitbucket.org/tildeslash/monit/src/master/)) `AGPL-3.0``C`
- [Naemon](http://www.naemon.org/) - Network monitoring tool based on the Nagios 4 core with performance enhancements and new features. ([Source Code](https://github.com/naemon/naemon-core)) `GPL-2.0``C`
- [Netdata](https://www.netdata.cloud/) - Distributed, real-time, performance and health monitoring for systems and applications. Runs on Linux, FreeBSD, and MacOS. ([Source Code](https://github.com/netdata/netdata)) `GPL-3.0``C`
- [NetXMS](https://www.netxms.org/) - Open Source network and infrastructure monitoring and management. ([Source Code](https://github.com/netxms/netxms)) `LGPL-3.0/GPL-3.0``Java/C++/C`
- [PHP Server Monitor](https://www.phpservermonitor.org/) - Open source tool to monitor your servers and websites. ([Source Code](https://github.com/phpservermon/phpservermon))
- [PhpSysInfo](https://phpsysinfo.github.io/phpsysinfo/) - A customizable PHP script that displays information about your system nicely. ([Source Code](https://github.com/phpsysinfo/phpsysinfo))
- [Prometheus](https://prometheus.io/) - Service monitoring system and time series database. ([Source Code](https://github.com/prometheus/prometheus)) `Apache-2.0``Go`
- [pyDash](https://k3oni.github.io/pydash/) - Small web-based monitoring dashboard for linux. ([Source Code](https://gitlab.com/k3oni/pydash))
- [Riemann](http://riemann.io/) - Flexible and fast events processor allowing complex events/metrics analysis. ([Source Code](https://github.com/riemann/riemann))
- [rtop](https://github.com/rapidloop/rtop) - an interactive, remote system monitoring tool based on SSH. ([Source Code](https://github.com/rapidloop/rtop))
- [ruptime](https://github.com/alexmyczko/ruptime) - classic system status server ([Source Code](https://github.com/alexmyczko/ruptime)) `AGPL-3.0``Shell`
- [Status](https://github.com/dani3l0/Status) - Simple and lightweight system monitoring tool for small homeservers with a pleasant web interface. ([Demo](https://status-ksk5.onrender.com/)) `MIT``Python`
- [Thruk](http://www.thruk.org/) - Multibackend monitoring web interface with support for Naemon, Nagios, Icinga and Shinken. ([Source Code](https://github.com/sni/Thruk))
- [Zabbix](http://www.zabbix.com/) - Enterprise-class software for monitoring of networks and applications. ([Source Code](https://git.zabbix.com/projects/ZBX/repos/zabbix/browse))
- [Beats](https://www.elastic.co/beats/) - Single-purpose data shippers that send data from hundreds or thousands of machines and systems to Logstash or Elasticsearch. ([Source Code](https://github.com/elastic/beats)) `Apache-2.0`
- [Diamond](https://github.com/python-diamond/Diamond) - Daemon that collects system metrics and publishes them to Graphite (and others). `MIT``Python`
- [RRDtool](https://oss.oetiker.ch/rrdtool/) - Industry standard, high performance data logging and graphing system for time series data. ([Source Code](https://github.com/oetiker/rrdtool-1.x)) `GPL-2.0``C`
- [Statsd](https://github.com/etsy/statsd/) - Daemon that listens for statistics like counters and timers, sent over UDP or TCP, and sends aggregates to one or more pluggable backend services. `Nodejs``MIT`
- [tcollector](http://opentsdb.net/docs/build/html/user_guide/utilities/tcollector.html) - Gathers data from local collectors and pushes the data to OpenTSDB. ([Source Code](https://github.com/OpenTSDB/tcollector/)) `LGPL-3.0/GPL-3.0``Python`
- [Telegraf](https://github.com/influxdata/telegraf) - Plugin-driven server agent for collecting, processing, aggregating, and writing metrics. `MIT``Go`
- [OpenWISP](https://openwisp.org/) - Open Source Network Management System for OpenWRT based routers and access points. ([Demo](https://openwisp.org/demo.html), [Source Code](https://github.com/openwisp)) `GPL-3.0``Python`
- [phpIPAM](http://phpipam.net/) - Open source IP address management with PowerDNS integration. ([Source Code](https://github.com/phpipam/phpipam)) `GPL-3.0``PHP`
- [RANCID](http://www.shrubbery.net/rancid/) - Monitor network devices configuration and maintain history of changes. ([Source Code](https://github.com/haussli/rancid)) `BSD-3-Clause``Perl/Shell`
- [DadaMail](http://dadamailproject.com/) - Mailing List Manager, written in Perl.
- [Lewsnetter](https://github.com/bborn/lewsnetter) - E-mail marketing application (create and send e-mail newsletter via SES). Includes subscription management, delivery, bounce and complaint notification, templates, and some stats.
- [Remmina](https://www.remmina.org/) - Feature-rich remote desktop application for linux and other unixes. ([Source Code](https://gitlab.com/Remmina/Remmina))
- [X2go](https://wiki.x2go.org/doku.php) - X2Go is an open source remote desktop software for Linux that uses the NoMachine/NX technology protocol. ([Source Code](https://code.x2go.org/gitweb))
- [DD-WRT](https://dd-wrt.com/) - A Linux-based firmware for wireless routers and access points, originally designed for the Linksys WRT54G series. ([Source Code](https://svn.dd-wrt.com/)) `GPL-2.0``C`
- [OpenWrt](https://openwrt.org/) - A Linux-based router featuring Mesh networking, IPS via snort and AQM among many other features. ([Source Code](https://git.openwrt.org/openwrt/openwrt.git)) `GPL-2.0``C`
- [OPNsense](https://opnsense.org/) - An open source FreeBSD-based firewall and router with traffic shaping, load balancing, and virtual private network capabilities. ([Source Code](https://github.com/opnsense)) `BSD-2-Clause``C``PHP`
- [pfSense CE](https://www.pfsense.org/) - Free network firewall distribution, based on the FreeBSD operating system with a custom kernel and including third party free software packages for additional functionality. ([Source Code](https://github.com/pfsense/pfsense)) `Apache-2.0``Shell/PHP/Other`
- [Consul](https://www.consul.io/) - Consul is a tool for service discovery, monitoring and configuration.
- [Doozerd](https://github.com/ha/doozerd) - Doozer is a highly-available, completely consistent store for small amounts of extremely important data.
- [etcd](https://github.com/coreos/etcd) - distributed K/V-Store, authenticating via SSL PKI and a REST HTTP Api for shared configuration and service discovery.
- [ZooKeeper](http://zookeeper.apache.org/) - ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services.
- [Podman](https://podman.io) - Daemonless container engine for developing, managing, and running OCI Containers on your Linux System. Containers can either be run as root or in rootless mode. Simply put: `alias docker=podman`. ([Source Code](https://github.com/containers/podman)) `Apache-2.0``Go`
- [systemd-nspawn](https://www.freedesktop.org/software/systemd/man/systemd-nspawn.html) - Lightweight, chroot-like, environment to run an OS or command directly under systemd. ([Source Code](https://github.com/systemd/systemd)) `GPL-2.0``C`
- [grml](https://grml.org) – bootable Debian Live CD with powerful CLI tools.
- [mitmproxy](http://mitmproxy.org/) - A Python tool used for intercepting, viewing and modifying network traffic. Invaluable in troubleshooting certain problems.
- [mtr](https://www.bitwizard.nl/mtr/) - Network utility that combines traceroute and ping.
- [perf-tools](https://github.com/brendangregg/perf-tools) - Performance analysis tools based on Linux perf_events (aka perf) and ftrace.
- [Sysdig](http://www.sysdig.org/) - Capture system state and activity from a running Linux instance, then save, filter and analyze.
- [Wireshark](https://www.wireshark.org/) - The world's foremost network protocol analyzer.
- [ConVirt](http://www.convirture.com/products_opensource.php) - Provides the core functionality for centrally managing your KVM or Xen virtualized environment.
- [Ganeti](http://www.ganeti.org/) - Cluster virtual server management software tool built on top of KVM and Xen.
- [KVM](http://www.linux-kvm.org) - Linux kernel virtualization infrastructure.
- [OpenNebula](http://opennebula.org/) - Flexible enterprise cloud made simple.
- [PiVPN](https://www.pivpn.io/) - The simplest way to setup and manage a VPN, designed for Raspberry Pi. ([Source Code](https://github.com/pivpn/pivpn)) `MIT``Shell`
- [Algernon](https://algernon.roboticoverlords.org/) - Small self-contained pure-Go web server with Lua, Markdown, HTTP/2, QUIC, Redis and PostgreSQL support. ([Source Code](https://github.com/xyproto/algernon)) `BSD-3-Clause``Go`
- [Apache HTTP Server](https://httpd.apache.org/) - Secure, efficient and extensible server that provides HTTP services in sync with the current HTTP standards. ([Source Code](https://svn.apache.org/viewvc/httpd/httpd/branches/2.4.x/)) `Apache-2.0``C`
- [Caddy](https://caddyserver.com/) - Powerful, enterprise-ready, open source web server with automatic HTTPS. ([Source Code](https://github.com/caddyserver/caddy)) `Apache-2.0``Go`
- [HAProxy](https://www.haproxy.org/) - Very fast and reliable reverse-proxy offering high availability, load balancing, and proxying for TCP and HTTP-based applications. ([Source Code](https://git.haproxy.org/?p=haproxy.git;a=tree)) `GPL-2.0``C`
- [Hiawatha](https://www.hiawatha-webserver.org/) - An advanced and secure webserver for Unix. ([Source Code](https://gitlab.com/hsleisink/hiawatha)) `GPL-2.0``C`
- [Lighttpd](https://www.lighttpd.net/) - Secure, fast, compliant, and very flexible web server that has been optimized for high-performance environments. ([Source Code](https://git.lighttpd.net/lighttpd/lighttpd1.4)) `BSD-3-Clause``C`
- [Nginx](https://nginx.org/en/) - HTTP and reverse proxy server, mail proxy server, and generic TCP/UDP proxy server. ([Source Code](https://hg.nginx.org/nginx/file/tip)) `BSD-2-Clause``C`
- [AlternativeTo](http://alternativeto.net) - Find alternatives to software you know and discover new software.
- [deb.sury.org](https://deb.sury.org/) - Repository with LAMP updated packages for Debian and Ubuntu.
- [ElRepo](http://elrepo.org/tiki/tiki-index.php) - Community Repo for Enterprise Linux (RHEL, CentOS, etc).
- [EPEL](https://fedoraproject.org/wiki/EPEL) - Repository for RHEL and compatibles (CentOS, Scientific Linux).
- [IUS](https://ius.io/) - Community project that provides RPM packages for newer versions of select software for Enterprise Linux distributions.
- [Remi](http://rpms.famillecollet.com/) - Repository with LAMP updated packages for RHEL/Centos/Fedora.
- [Software Collections](https://www.softwarecollections.org) - Community Release of [Red Hat Software Collections](https://access.redhat.com/documentation/en/red-hat-software-collections/). Provides updated packages of Ruby, Python, etc. for CentOS/Scientific Linux 6.x.
- [Awesome SysAdmin @ LibHunt](https://sysadmin.libhunt.com) - Your go-to SysAdmin Toolbox. Based on the list here.
- [Ops School](http://www.opsschool.org) - Comprehensive program that will help you learn to be an operations engineer.
- [Digital Ocean Tutorials](https://www.digitalocean.com/community/tutorials) - A surprisingly vast resource for getting the basics of certain applications, tools, or even systems administration topics.
