SlaveCode LogoSlaveCode.
Academy
RoadmapProblemsSystem Design
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
SlaveCode LogoSlaveCode.

Standardize your coding journey. From basic academy courses and guided roadmaps to advanced system design, company interview prep, and real-time coding arenas. The all-in-one platform to master algorithms and prove your engineering excellence.

Learn & Practice

  • Academy
  • Problems
  • Roadmap
  • System Design

Compete & Tools

  • Arena
  • Contests
  • Compilers

Legal & Support

  • Report an Issue
  • Privacy Policy
  • Terms of Service
  • Contact Us

© 2026 SlaveCode. All rights reserved.

Emacs Lisp

Emacs Lisp

Emacs Lisp is the extension language of the Emacs text editor. You can easily create you own extensions, which include preference files, but also full-fledged applications that use Emacs as a running environment in a fully integrated way.

Master Emacs Lisp with
Interactive Learning

Elevate your Emacs Lisp skills through 98 curated exercises across 0 core concepts. Master problem-solving with a structured learning path designed for modern developers.

Emacs Lisp

About Emacs Lisp

Emacs Lisp is the language at the core of Emacs, the iconic text editor that is at the beginning of the Free Software movement. Emacs is made of more than a million lines of Emacs Lisp, and all the applications that run inside Emacs (IDEs for various programming languages, games, planners, etc.) are written in Emacs Lisp. User preferences are also lists of Emacs Lisp expressions.

Knowing Emacs Lisp is the first step into Lisp, the second oldest programming language still used (just turned 60 in 2018) and also a language that still influences so many other programming languages.

Quoting the creator of Emacs: "Multics Emacs proved to be a great success — programming new editing commands was so convenient that even the secretaries in his office started learning how to use it. They used a manual someone had written which showed how to extend Emacs, but didn't say it was a programming. So the secretaries, who believed they couldn't do programming, weren't scared off. They read the manual, discovered they could do useful things and they learned to program."

Key Features of Emacs Lisp

Simple syntax

Emacs Lisp's syntax is simple, expressive and easy to learn.

S-expressions

Both source code and data are expressed using nested lists.

Macros

It's easy to customize the language with Emacs Lisp's macro system.

Multi-paradigm

Emacs Lisp support imperative and functional programming styles.

Scripting

Emacs Lisp can be used as scripting language by using Emacs' batch mode.

Well Documented

Emacs Lisp is well documented right inside the editor.

Track icon

Simple syntax

Emacs Lisp's syntax is simple, expressive and easy to learn.

S-expressions

Both source code and data are expressed using nested lists.

Macros

It's easy to customize the language with Emacs Lisp's macro system.

Multi-paradigm

Emacs Lisp support imperative and functional programming styles.

Scripting

Emacs Lisp can be used as scripting language by using Emacs' batch mode.

Well Documented

Emacs Lisp is well documented right inside the editor.

Dive into Emacs Lisp practice challenges

Hello World
Hello World
Level 1

SlaveCode's classic introductory exercise. Just say "Hello, World!".

Accumulate
Accumulate
Level 2

Implement the `accumulate` operation, which, given a collection and an operation to perform on each element of the collection, returns a new collection containing the result of applying that operation to each element of the input collection.

Acronym
Acronym
Level 2

Convert a long phrase to its acronym.

Allergies
Allergies
Level 2

Given a person's allergy score, determine whether or not they're allergic to a given item, and their full list of allergies.

Armstrong Numbers
Armstrong Numbers
Level 2

Determine if a number is an Armstrong number.

Binary
Binary
Level 2

Convert a binary number, represented as a string (e.g. '101010'), to its decimal equivalent using first principles.