Not only Clojure — Chez Scheme: lisp with native code speed

Volodymyr Pavlyshyn
2 min readSep 19, 2023


Chez Scheme is a high-performance, industrial-strength Scheme compiler that has been around for decades. It is renowned for its efficiency, robustness, and extensive features. Scheme, a dialect of Lisp, is known for its simplicity and elegance, making it a popular choice for academic research and industrial applications. Chez Scheme takes this further by offering optimizations and features that make it suitable for high-performance computing tasks.

In this article, we’ll delve deep into the architecture, features, and use cases of Chez Scheme. We’ll also explore why it stands out among other Scheme implementations and how it can be a valuable tool for software developers interested in functional programming.

Architecture and Design

Chez Scheme is designed with performance in mind. It employs a nanopass compiler framework, which breaks down the compilation process into small, manageable steps. This allows for greater flexibility and optimization at each stage. The compiler generates highly optimized machine code, which is one of the reasons for its exceptional performance.


The nanopass architecture allows for a modular approach to compiler design. Each pass performs a specific transformation, making it easier to understand, debug, and extend the compiler. This is particularly beneficial for those who want to dive into the compiler's internals, perhaps to add new features or optimizations.


  1. Optimizing Compiler: Chez Scheme’s compiler is known for generating highly optimized code. It performs various optimizations like inlining, constant folding, and dead-code elimination.
  2. Foreign Function Interface (FFI): Chez Scheme provides a robust FFI, allowing it to call C functions and vice versa. This is particularly useful for integrating with existing libraries or for performance-critical sections of code.
  3. Concurrency: While the Scheme doesn’t have built-in concurrency features, Chez Scheme provides a set of primitives for thread management, making it easier to write concurrent programs.
  4. Debugging and Profiling: Chez Scheme has a comprehensive set of debugging and profiling tools, making it easier to identify bottlenecks and debug issues.
  5. R6RS Compliance: Chez Scheme is one of the few Scheme implementations that are fully compliant with the Revised⁶ Report on Scheme, ensuring a high level of standardization.


Chez Scheme is versatile and can be used in various domains, such as:

  • Scientific Computing
  • Web Development
  • Scripting
  • Systems Programming

Why Choose Chez Scheme?

If you’re a functional programming enthusiast, Chez Scheme offers a blend of performance and features that are hard to find in other Scheme implementations. Its optimizing compiler ensures you don’t have to compromise on speed, while its extensive feature set makes it suitable for a wide range of applications.


Chez Scheme is more than just another Scheme implementation; it’s a powerful, optimizing compiler that brings industrial-strength performance to the Scheme programming language. Whether you’re into academic research, industrial development, or simply a functional programming aficionado, Chez Scheme offers something.



Volodymyr Pavlyshyn

I believe in SSI, web5 web3 and democratized open data.I make all magic happens! dream & make ideas real, read poetry, write code, cook, do mate, and love.