Theme
Dependencies
Open-source libraries and tools that Code Treadmill builds on.
Runtime dependencies
| Library | How it's used |
|---|---|
| Judge0 | Self-hosted code execution sandbox — runs student submissions in isolated containers and returns output, errors, and exit status. |
| CodeMirror | In-browser code editor used for write exercises. |
| @replit/codemirror-vim | Vim keybindings for CodeMirror, enabling optional vim mode in write exercises. |
| Python doctest | Standard library module used to define and run visible + hidden tests for Python write exercises. |
| davidchambers/doctest | JavaScript doctest format (// > expr / // result) used for JS write exercises. |
| doctest (C++) | Lightweight C++ testing framework (CHECK() / TEST_CASE()) used for C++ write exercises. |
| APML (Baker Franke) | Converts AP pseudocode text to visual block diagrams for the AP CSP Pseudocode block view. |
| 8080js (Martin Maly) | Intel 8080 CPU emulator in JavaScript — assembles and executes 8080 assembly exercises server-side to produce the expected accumulator value. |
| styled-components | CSS-in-JS library used for all component styling and runtime theming. |
| Next.js | React framework providing routing, API routes, and server-side rendering. |
| Playwright | Used at dev-server startup to generate target screenshots for HTML/CSS exercises. |
Themes
Colour themes are adapted from the prism-themes collection. The following themes are included:
- Catppuccin
- Cobalt
- Dracula
- Duotone Dark
- Duotone Light
- GitHub
- Night Owl
- Night Owl Light
- Oceanic Next
- Okaidia
- Pale Night
- Shades of Purple
- Synthwave '84
- VS Dark
- VS Light
The selected theme is persisted in localStorage and applied site-wide, including on these documentation pages.