Decker
Decker is a multimedia platform for creating and sharing interactive documents, with sound, images, hypertext, and scripted behavior. You can try it in your web browser right now.
Decker builds on the legacy of HyperCard and the visual aesthetic of classic MacOS. It retains the simplicity and ease of learning that HyperCard provided, while adding many subtle and overt quality-of-life improvements, like deep undo history, support for scroll wheels and touchscreens, more modern keyboard navigation, and bulk editing operations.
Anyone can use Decker to create E-Zines, organize their notes, give presentations, build adventure games, or even just doodle some 1-bit pixel art. The holistic "ditherpunk" aesthetic is cozy, a bit nostalgic, and provides fun and distinctive creative constraints. As a prototyping tool, Decker encourages embracing a sketchy, imperfect approach. Finished decks can be saved as standalone .html documents which self-execute in a web browser and can be shared anywhere you can host or embed a web page. Decker also runs natively on MacOS, Windows, BSD, and Linux.
For more complex projects, Decker features a novel scripting language named Lil which is strongly influenced by both Lua, an imperative language popular for embedding in tools and game engines, and Q, a functional language in the APL family used with time-series databases. Lil is easy to learn and conventional enough not to ruffle any feathers for users with prior programming experience, but also includes pleasant surprises like implicit scalar-vector arithmetic and an integrated SQL-like query language. A few lines of Lil can go a long way.
Decker provides a small collection of built-in interactive widgets for building interfaces, as well as a facility for defining new ones. Custom widgets and their definitions can be copied and pasted using the system clipboard, which also makes it possible to share them anywhere you can share or store text. Every deck is a toolkit of reusable parts that can be harvested and repurposed for another project.
Decker is command-line friendly: when built from source, it comes with Lilt, a standalone Lil interpreter which can (among other things) read, write, manipulate, and even execute Decker documents "headlessly". Lilt has even fewer dependencies than Decker itself, so it can also be compiled as a cross-platform APE executable, ready for writing run-anywhere shell scripts. Would you believe there's a Lil interpreter that runs on POSIX AWK? Decks are stored in a line-oriented text format which interoperates well with existing source control tools like Git and SVN.
Decker includes no advertising, telemetry, gamification, slop-generator integration, or other intrusions on user privacy and autonomy. If you like Decker, please share it with other people who might enjoy it. Build something that makes you happy.
Examples
- Decker: A Guided Tour
- All About Draggable
- All About Sound
- All About Color
- All About Brushes
- All About Fonts
- All About Transitions
- 5GUIs
- Sokoban: A Block-Pushing Puzzle Game
- Breakout: Three Ways (Discussion)
- A CHIP-8 Interpreter
- Gamepad Input Demo
Libraries
- plot: Simple Graphing and Plotting
- stats: Statistical Math Utilities
- pdf: Portable Document Format Export
- twee: Read Twine's .twee File Format
- zazz: Animation Helpers
- ease: Easing Functions
- bn: Arbitrary-Precision Unsigned Integers
- dd: Visual-Novel Modals
- pt: Visual-Novel Sprite Animation
- path: Grid Pathfinding
- hershey: Vector Fonts
- dfxr: Sound Effect Generation
- WigglyKit: Juicy, Jiggly Drawing Components
- The Forbidden Library: Escaping Decker's Shackles, for a Price
Documentation
- The Decker reference manual
- The Lil programming language
- The Decker document format
- Learn Lil in 10 Minutes
- The Lil playground
- Lil Quick-reference card
- Lilt: the Lil Terminal
- Phinxel's Phield Notes: A Guide to Making Stuff in Decker
- A Multimedia Sketchpad
- Decker: Responding to Responses
Additional Resources
Browsable source code and a bug-tracker are available on GitHub. Decker is free and open-source, under a permissive MIT license.
Periodic binary release downloads for MacOS and Windows are available on Itch.io. The Itch page includes a community forum for discussing Decker and sharing projects made with Decker. We also hold Decker-themed "Game Jams" every July and December; the next upcoming jam will be Decker Fantasy Camp, July 2026.