fx · LedoCorp

A systems language that refuses hidden control. No garbage collector quietly rewriting your heap. No implicit allocator. No framework magic between what you wrote and what runs.

What it is

fx sits on top of the C universe without pretending C never existed. You get a sharper language for new code, and a first-class path back to readable C when you need to ship, embed, or wrap what you already have.

Every important decision (who allocates, who mutates, how long memory lives) is meant to stay visible in the source you open tomorrow, or that an agent generates tonight.

Core ideas

Effects · signatures declare alloc / mut so cost is local
Named regions · arena lifetimes you can see; batch free when the region ends (not a GC)
Dual emission · fx run / fx build, or fx emit-c for C you can audit
Wrap / host · C owns main, fx owns the logic; link mature C libraries instead of rewriting them
Small zspec substrate · explicit allocators and errors in the linked C world
Humans and agents · low-ceremony, mechanical style that stays auditable when generated

Who it’s for

Systems and embedded work that needs structure without surrendering the heap to a GC
Teams extending codebases that already speak C
People using AI assistants who still want inspectable, explicit programs

It is not a batteries-included app platform or a scripting GC language. This preview is a serious core: language + compiler + std foothold + C interop.

Try it

The language package ships on GitHub: prebuilt compiler (bin/), scaffolds, std/, docs, zspec headers/libs, examples, and optional inspectable compiler modules.

Requirements: this package · a C toolchain (gcc default) · Windows or Linux x86_64.

# put bin/ on PATH, then:
fx version                 # v0.7.0-preview
fx new hello
cd hello
fx run main.fx             # exit 42

fx new tiny --scaffold minimal
fx new firmware --scaffold embedded
fx emit-c main.fx -o out_c
fx run examples/showcase_wrap/compute.fx --host examples/showcase_wrap/host.c

github.com/ledocorp/fxlang Apache-2.0 · LedoCorp

What’s in the package

bin/fx / bin/fx.exe · how you run fx
scaffolds/ · std/ · docs/ · examples/
zspec/ + build/ · headers and libzspec for linking emitted C
compiler-source/ · read-only fx modules (lexer/parse/emit) for inspection; not a rebuild SDK

Tooling

The same binary includes fx lsp (editor) and fx mcp (lean agent tools: check / locate / run). Put fx on your PATH and wire Cursor or friends as you like.