Stillterm

Quiet character animation for terminals and native screensavers, powered by Rust.

Sparse streams, fading trails, and a small reusable animation engine. Stillterm runs directly in your terminal, with deterministic seeds and a 30 FPS default. It has no background service or browser runtime.

Engine snapshot: seed 42, four seconds, 96×28 cells. Font and brightness vary by terminal. An animation recording is planned for the first release.

Status: Terminal application plus macOS and Windows screensaver development builds, plus an experimental Hyprland adapter. macOS Developer ID signing is configured and the first package has been submitted for notarization. Public binary releases are pending; Windows builds remain unsigned. Stillterm does not lock your session.

Install

Requires Rust 1.88 or newer and a system linker. With rustup, this checkout selects the tested Rust 1.88.0 toolchain.

git clone https://github.com/saeedet/Stillterm.git
cd Stillterm
cargo install --path crates/terminal --locked

This installs stillterm into Cargo's binary directory. Ensure that directory is on your PATH. Uninstall with cargo uninstall stillterm.

Signed prebuilt downloads are not available yet. There is no published crates.io package at this stage; use the source installation above.

macOS screensaver

On macOS, build a universal native screensaver and try it in a window:

rustup target add aarch64-apple-darwin x86_64-apple-darwin
scripts/build-macos.sh
scripts/check-macos.sh --preview

Open target/macos/Stillterm.saver to install. It includes both themes and a native options panel. Local installed-screensaver testing passed on Apple M3 with macOS 14.6.1, including theme switching, multiple displays, sleep/wake, and cleanup after dismissal. Build 5 passes a retained-view memory regression check; after three installed previews, the idle helper measured 117 MiB and 0% CPU. Longer-session memory and active-rendering performance validation are still pending. Signed, notarized downloads and broader compatibility testing are also pending. See macOS setup and distribution.

Windows screensaver

On Windows, run ./scripts/build-windows.ps1 from PowerShell to build target/windows/Stillterm.scr. It supports full screen, native settings, and the embedded Windows preview. The manual checklist passed on Windows 10 and Windows 11. Milestone 3 implementation and manual testing are complete. This remains an unsigned development build. See setup and the test checklist.

Linux / Hyprland

An experimental adapter runs Stillterm in one Foot terminal per monitor, with input dismissal and cleanup on locking or display changes. Install and try it using the Linux guide. Standalone Hypridle integration is optional; Omarchy 4.0.4 supports manual preview only because its current idle service has no suitable replacement interface. Physical Linux desktop validation remains pending.

Run

stillterm
stillterm run --fps 30 --seed 42
stillterm --speed 0.6 --density 0.12
stillterm --config examples/config.toml
stillterm list

Press q, Escape, or Ctrl+C to quit. Resize the terminal while it runs. For development without installation, use cargo run --release -- --seed 42. Use an ANSI-capable terminal; Windows Terminal is the intended Windows surface.

Matrix theme

stillterm --theme matrix
stillterm --config examples/matrix.toml

Green trails, pale heads, and half-width Katakana mixed with digits and symbols. The preset uses speed 1.6, density 0.35, and intensity 1.0; explicit file or CLI settings override those defaults. The original look remains the default and is available as --theme monochrome.

Engine snapshot using the theme's ideal colors; terminal palettes and fonts vary.

Use a font with half-width Katakana support. For an ASCII fallback, add --characters '0123456789:<>*+-'. Standard terminal glyphs cannot reproduce the movie's mirrored characters. True-color terminals show the smoothest green ramp; 256-color and basic-color terminals use reduced palettes. NO_COLOR disables color.

Configure

Settings apply in this order: built-in defaults, an explicitly supplied TOML file, then command-line overrides. The selected theme supplies defaults for omitted visual settings. Files must be UTF-8 TOML, no larger than 64 KiB. No configuration file is written automatically.

These settings configure the terminal and Linux adapter. The macOS and Windows screensavers use their own Options/Settings panels and per-user preferences; changing a CLI file does not change either native screensaver.

Setting	Default	Accepted values
effect	"rain"	rain
theme	"monochrome"	monochrome, matrix
fps	30	Integer, 10–60
speed	1.0	0.1–4.0
density	0.18	0.0–1.0; stream activation probability
intensity	0.7	0.0–1.0
characters	"0123456789.:+*"	1–256 printable, single-column characters
seed	42	Unsigned 64-bit integer

See the example configuration or stillterm --help. The numeric and character defaults in the table describe the monochrome theme. ASCII is the most portable character set. Wide, combining, control, and ambiguous-width characters are rejected. Nonempty NO_COLOR disables color; the monochrome theme otherwise uses a detected grayscale or basic-color palette.

Platforms

Surface	Status
macOS terminal	Tested locally on Apple Silicon, including PTY lifecycle checks
Windows terminal	Cross-checked for compilation; native CI configured; interactive testing pending
Linux terminal	Cross-checked for compilation; native CI and PTY checks configured
macOS .saver	Installed screensaver tested on Apple M3 / macOS 14.6.1; Intel slice checked under Rosetta; signed downloads pending
Windows .scr	Manual checklist passed on Windows 10 and Windows 11; unsigned x64 build
Hyprland / Hypridle	Experimental adapter; automated lifecycle tests; desktop acceptance pending
Omarchy 4.0.4	Manual preview path; automatic idle replacement unsupported

CI checks the workspace and macOS bundle, plus Linux launcher and terminal lifecycle tests. The optional Linux adapter provides desktop integration around the terminal executable. See platform research and acceptance checks.

How it works

stillterm-engine owns a character grid, seeded rain state, and fixed simulation steps. stillterm owns the terminal, configuration loading, timing, and input. The renderer compares presented cells and writes changed runs. The engine has no OS or graphical-framework dependencies. Engine and CLI crates forbid unsafe Rust; the macOS bridge isolates the documented C interface.

On the initial Apple M3 benchmark, the CLI used less than 1% of one CPU core at 30 FPS in a drained pseudo-terminal. This excludes terminal-emulator rendering; see measurements and reproduction steps.

For the boundaries and determinism contract, read architecture. To extend the engine, read adding an effect.

Contribute

cargo test --workspace --all-targets --locked
cargo fmt --all --check
cargo clippy --workspace --all-targets --locked -- -D warnings

Contributing covers platform checks, visual changes, and bug reports. See the development changelog for implemented changes and remaining limits. Licensed under MIT.