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The C3 Guide

Hello, the C3 Guide is a guide to the C3 Programming Language. It is a work in progress, and will be continually updated.

What is C3?

C3 is a system programming language based on C. It is an evolution of C enabling the same paradigms and retaining the same syntax as far as possible.


  • Full C ABI compatibility
  • Module system
  • Generic modules
  • Design by contract
  • Zero overhead errors
  • Semantic macro system
  • First-class SIMD vector types
  • Struct subtyping
  • Safe array access using slices
  • Easy to use inline assembly
  • Cross-platform standard library which includes dynamic containers and strings
  • LLVM backend