GoKawiil09 Jul 2026 Charles Choi
A common refrain is that Emacs is an operating system (OS). This isn’t true, but what invites comparison to an OS is its ability to orchestrate applications and utilities above the OS kernel level. The diagram below suggests a truer picture of how Emacs’ relates to an OS and its capabilities.
Emacs’ built-in access to OS system services (file system, network, etc.) coupled with the ability to run other programs makes it routine to improvise client behavior within it. Because of this, Emacs users are able to accomplish many of their computing needs from the different client modes that have been made for it. This gives credence to the notion of “living only in Emacs.”
In this post, we’ll examine some of the ways Emacs lets you build a client. By the end of this post, you’ll hopefully be convinced that from within Emacs, everything looks like a service.
Client-Server Model
Let’s first provide some definitions.
The Client–Server model is a common computer interaction pattern where a task is partitioned between the provider of a resource (the service) and the requester of that resource (the client). The client issues a request to the server, and the server in turn returns a response as shown in the diagram below.
Depending on the implementation, the transaction (request + response) can occur over a network or be local to a system. Client-server models using a network has been most elaborated upon with REST-style software architectures. Shown in the sequence diagram below is a common implementation pattern for REST-style client server architecture.
Emacs as a Client
From the diagram above, there are three concerns the client is typically responsible for:
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