Repository: https://github.com/fetlang/fetlang

Fetlang is a statically typed, procedural, esoteric programming language and reference implementation. It is designed such that source code looks like poorly written fetish erotica

Fetlang is not recommended for production use at this moment, especially in medical or military applications


The following example outputs the arguments given to the executable:

Make Sean moan
Worship Carrie's feet

Bind Amy to Saint Andrew's Cross
    Have Amy hogtie Sean
    If Amy is Carrie's bitch
        Make Slave scream Sean's name
        Make Sean moan


  • Input/output with standard streams and files
  • Statically typed
  • Gendered variables
  • Access previously mentioned variables using pronouns
  • Numbers represented internally as fractions instead of floating point
  • Transpiles to C
  • Confusing English-like syntax and unhelpful error messages
  • Turing complete (See here for a Rule 110 implementation by Kjeld Schmidt)
  • Has a Vim plugin (thanks to Kutsan Kaplan)
  • Can be extended with C, C++, or Rust



  • meson
  • ninja
  • gcc/g++(>=4.9) or clang(>=3.5)

Optional dependencies:

  • boost algorithm(>=1.62)
  • boost filesystem(>=1.62)
  • boost system(>=1.62)

Supported systems:

  • macOS (tested with Travis CI)
  • GNU/Linux (tested with Travis CI)
  • Other modern Unix-like systems
  • Windows 10 under WSL/WSL2

Build Fetlang:

$ git clone https://github.com/fetlang/fetlang
$ cd fetlang
$ meson --buildtype=release src build
$ cd build
$ # Build Fetlang
$ ninja
$ # Run unit tests
$ ninja test

The build will use the version of Boost included in Fetlang by default. If you want to use your system’s version of boost, you can run meson configure -Duse_system_boost=true in the build folder

Install Fetlang:

$ sudo ninja install
$ # Make sure it worked
$ fetlang ../examples/hello.fet && ./a.out
Hello World!