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 ( https://dungeons.fetishclubsreviews.org/ ).

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!