Best Armed Bear Common Lisp Alternatives & Competitors in 2025

Steel Bank Common Lisp (SBCL) is a high performance Common Lisp compiler.

Key Steel Bank Common Lisp features:

Performance Standards Compliance Actively Maintained Robust Debugging Tools

Open Source

Clozure CL (often called CCL for short) is a free Common Lisp implementation with a long history.

Key Clozure Common Lisp features:

High Performance Cross-platform Support Dynamic Typing and Flexibility Interactivity

Open Source

Flagsmith lets you manage feature flags and remote config across web, mobile and server side applications. Deliver true Continuous Integration. Get builds out faster. Control who has access to new features. We're Open Source.

Key Flagsmith features:

Feature Flags Remote Config A/B/X Testing & Optimization Organization Management

Try for free Open Source freemium

CLISP is a portable ANSI Common Lisp implementation and development environment by Bruno Haible.

Key CLISP features:

Cross-platform compatibility GNU Licensing Interpreter environment ANSI Common Lisp compliance

CMUCL is a high-performance, free Common Lisp implementation.

Key CMU Common Lisp features:

High-Performance Compiler Extensive Library Support Strong Typing System Garbage Collection

Leading commercial Enterprise Development Tools and dynamic object-oriented Common Lisp development tools including Allegro CL with AllegroCache, an Object Database that provides Object Persistence in Lisp, native to the Lisp langauge.

Key Allegro CL features:

Performance Rich Development Environment Advanced Features Dynamic Language

Hy is a wonderful dialect of Lisp that’s embedded in Python.

Key Hy features:

Python Interoperability Lisp Syntax and Macros Readability Compiles to Python

ManKai Common Lisp (MKCL) aims to be a full implementation of the Common Lisp language in...

Key ManKai Common Lisp features:

Compatibility Performance Portability Open Source

Guile is the GNU Ubiquitous Intelligent Language for Extensions, the official extension language for the GNU operating system.

Key Guile features:

Extensibility Scheme Language Integration with C Garbage Collection

newLISP is a general purpose scripting language for developing web applications and programs in general in the domains of artificial intelligence (AI), statistics and machine learning.

Clojure is a dynamic, general-purpose programming language, combining the approachability and interactive development of a scripting language with an efficient and robust infrastructure for multithreaded programming.

Key Clojure features:

Functional Programming Paradigm Interoperability with Java REPL Driven Development Concise Syntax

Open Source

Racket (formerly PLT Scheme) is a modern programming language in the Lisp/Scheme family, suitable...

Key Racket Lang features:

Metaprogramming Rich Libraries Educational Use Interactive Development

Open Source

Implementation of Scheme providing an interpreter, compiler, source-code debugger, integrated Emacs-like editor, and a large run-time library.

Nu is an interpreted object-oriented programming language, with a Lisp-like syntax, it was created...