Frothy is a small live lexical language for programmable devices.

to pulse with pin, wait [
  gpio.high: pin;
  ms: wait;
  gpio.low: pin
]

to blink with pin [
  repeat 3 [
    pulse: pin, 75;
    ms: 75
  ]
]

blink: LED_BUILTIN
save

Frothy keeps the strongest substrate traits from Froth and changes the public model where it needed to change. The language is built around stable named slots, lexical scopes, non-capturing Code, explicit persistence, and direct inspection of the live device image.

Live Image, Not Upload Cycles

The running image is split into a boot-time base image and a live overlay. Top-level names keep a stable identity while their current values can be rebound. save, restore, and dangerous.wipe let you checkpoint, recover, and reset that overlay without pretending the device is disposable.

Lexical, Inspectable, Device-First

Frothy deliberately does not preserve Froth’s old stack-centric user model. Everything user-facing is either a value or a place that holds one. Blocks are lexical. Code is just another value. Inspection is part of ordinary work: words, show, see, core, and info are built into the maintained interactive surface.

Built For Real Boards

Frothy is embedded-device-first. Host and local paths exist to make development faster, but the maintained proof path stays on connected ESP32 hardware. The first public protoboard target on this site is the TM1629-based esp32-devkit-v4-game-board, with the shared base-image board library documented underneath it.

On this site, that protoboard is introduced as the Froth Machine : the display, joystick, knobs, and small game-shaped workflow you can learn in a workshop without reading low-level board reference first.

Start Here

• Install Frothy for the maintained CLI, VS Code, and board path.
• Read the guide for the language and workflow from first principles.
• Explore the Machine for the Froth Machine board, its words, its controls, and its first games.
• Use the reference when you need exact behavior or library surface details.
• Read how Frothy differs for the breaks from Froth and the reasons behind them.

The product is Frothy, but the installed CLI command is still froth during the current transition. That naming split is deliberate and documented.