CRT's a Ridiculous Terminal

Why

I really like Hyper.js, being able to use CSS to style a terminal just made it fun, but it's not been maintained and has been regressing in performance recently. So like anyone who hasn't tried to do the thing before I decided "How hard could it be ?". This is the result, it's not as performant as rio or alacritty, but I'm pretty sure we're eating up less memory than Hyper and I'm not getting weird pinwheels of doom as I use it - and I'm doing way more rendering so I'm taking it as a win.

Also, my 6 year old thinks its cool so what other possible endorsements could you want ?

"This is cool!"

— Mat (6 years old)

Features

• GPU Rendering - Hardware-accelerated rendering via wgpu/vello for smooth 60fps performance
• CSS Theming - Fully customizable themes using CSS syntax with hot-reload support
• Visual Effects - CRT scanlines, matrix rain, particle systems, perspective grids, animated sprites
• 256-Color Support - Full ANSI color palette with per-theme overrides for tools like LS_COLORS
• Tabs - Multi-tab support with customizable tab bar styling
• Font Ligatures - Programming ligature support with configurable font variants

Installation

macOS

curl -sSL https://raw.githubusercontent.com/colliery-io/crt/main/scripts/install.sh | sh

This installs crt.app to /Applications and sets up config at ~/.config/crt/.

Linux (un tested )

curl -sSL https://raw.githubusercontent.com/colliery-io/crt/main/scripts/install.sh | sh

Binary installs to ~/.local/bin/crt with config at ~/.config/crt/.

Windows Support

Soon™

Building from Source

Requires Rust 2024 edition:

git clone https://github.com/colliery-io/crt.git
cd crt
cargo build --release

Quick Start

After installation:

1. Launch CRT from Applications (macOS) or run crt (Linux)
2. Try different themes by editing ~/.config/crt/config.toml:

   [theme]
   name = "matrix"  # or "nyancat", "synthwave", "minimal", etc.

3. Save the file and press Cmd+N to open a new window with the theme
4. See all available themes: ls ~/.config/crt/themes/

Note: Colors and effects hot-reload on save, but background images and sprites require a new window (Cmd+N) to load.

Configuration

Configuration lives at ~/.config/crt/config.toml:

Themes

CRT includes 16 built-in themes. See the Theme Gallery for screenshots of each.

Theme	Description
alien	Amber phosphor CRT (Weyland-Yutani MU/TH/UR 6000)
dracula	Classic Dracula color scheme
matrix	Green falling code with CRT effect
minimal	Clean, pure black background
nyancat	Bouncing Nyan Cat with stars and sparkles
particles	Floating particle effect
rain	Animated rain drops
robco	Fallout Pip-Boy green phosphor CRT
shape	Floating geometric shapes
solarized	Solarized Dark color scheme
starfield	Twinkling stars background
stress	All effects at once (for testing)
synthwave	80s neon with perspective grid
tron	Cyan grid aesthetic
vaporwave	Pink and cyan aesthetic with perspective grid
wh40k	Warhammer 40K Adeptus Mechanicus with servo skull

Custom Themes

Create custom themes at ~/.config/crt/themes/mytheme.css and set name = "mytheme" in config.

See the Theming Guide for details, or jump to:

• How to Create a Custom Theme
• CSS Properties Reference

Keyboard Shortcuts

Windows & Tabs

Shortcut	Action
Cmd+N	New window
Cmd+T	New tab
Cmd+W	Close tab
Cmd+1-9	Switch to tab 1-9
Cmd+Shift+[	Previous tab
Cmd+Shift+]	Next tab
Double-click tab	Rename tab

Navigation

Shortcut	Action
Page Up	Scroll up through history
Page Down	Scroll down through history
Home	Jump to top of scrollback
End	Jump to bottom
Cmd+Click	Open URL under cursor

Search

Shortcut	Action
Cmd+F	Open search
Enter	Find next match
Escape	Close search

Font Size

Shortcut	Action
Cmd+=	Increase font size
Cmd+-	Decrease font size
Cmd+0	Reset font size

Other

Shortcut	Action
Cmd+C	Copy selection
Cmd+V	Paste
Right-click	Context menu
Cmd+Option+P	Toggle profiling

Troubleshooting

Fonts look wrong or missing characters

• CRT bundles MesloLGS NF (a Nerd Font) which is installed to ~/.config/crt/fonts/
• If you see boxes or missing glyphs, the font may not be loading - check the config font family setting

Theme not loading

• Check that the theme file exists at ~/.config/crt/themes/{name}.css
• Check the terminal output for CSS parsing errors
• Colors and effects hot-reload on save; background images and sprites need a new window (Cmd+N)

Performance issues

• Themes with multiple backdrop effects (particles + matrix + sprites) use more resources than simpler themes
• Try minimal or dracula if you want a lightweight option

Reporting Issues

Found a bug? Enable profiling with Cmd+Option+P, reproduce the issue, then submit a bug report with the profile log from ~/.config/crt/.

Open an issue

Contributing

Open a PR

License

MIT