Learn Joule.
One language for real programs, with energy as a first-class observable. Everything here is also writable right now in the playground.
Install & quickstart
Install the joulec toolchain, create a project, build it, and read your first energy receipt. A few minutes, no account.
Language guide
Types and inference, pattern matching, generics, functions, and the energy annotations that make cost visible where you write it.
Energy accounting
How Joule attributes energy per function and operation, what a receipt contains, and how budgets are checked at build time.
Standard library
The modules that ship with Joule, with energy notes throughout: collections, algorithms, numerics, text, concurrency, and I/O.
Benchmarks & targets
How Joule performs, why compiling to C keeps native energy close to C, and which targets the toolchain produces.
The self-hosting compiler
How the compiler is written in Joule, compiles itself to C, and reaches a byte-identical fixed point, with the 514+ program corpus as its test suite.
Prefer to just try it?
The playground checks, runs, and energy-estimates Joule in your browser. Nothing leaves the page.