From science fiction: Ursula K. Le Guin coined the word "ansible" in her 1966 novel Rocannon's World for a device that communicates instantly across interstellar distances.

In Le Guin's Hainish books an ansible lets people talk across light-years with no delay, which is useful when your spaceships are slower than light. The word was picked up by other authors (Orson Scott Card's Ender's Game uses it too) and became a standard sci-fi term.

The name fits the tool: Ansible's job is to send instructions from one central place to many distant machines at once, and have them all act on them.

Go deeper:

• Rocannon's World (Ursula K. Le Guin official site) — the author's own page for the 1966 novel, noting it is where she coined "ansible".
• Ansible (Wikipedia) — how the fictional device spread from Le Guin to Card and other sci-fi writers.

Ansible, Puppet and Chef. All three are relatively easy to learn, exist as open-source versions, and use plugins and adapters to control many kinds of resources.

These three dominate classic configuration management, the job of putting and keeping servers in a defined configuration. Their shared traits explain why they spread so widely:

• Relatively easy to learn: you describe configuration in a readable language instead of writing shell scripts from scratch.
• Open-source versions exist: teams can start for free and buy commercial support later.
• Plugins and adapters: the core stays small, and extensions let it control operating systems, cloud APIs, databases and network devices, directly or indirectly.

Puppet was the first of the modern tools: released as open source in 2005, then commercialised by Puppet Labs as Puppet Enterprise in 2011. Chef followed in 2009 and Ansible in 2012.

Go deeper:

• Comparison of open-source configuration management software (Wikipedia) — side-by-side tables of Ansible, Puppet, Chef, Salt and others: language, agent, push/pull, platforms.
• Puppet (software) (Wikipedia) — history from the 2005 open-source release, and its agent-based pull model.
• Progress Chef (Wikipedia) — the 2009 Ruby-based tool and its recipe/cookbook model.