Zenkai: The App Launcher I Wrote Because I Wanted Something Fast and Beautiful

Description and use

Zenkai is a cross‑platform launcher built with Zig and Qt6 that opens in 140 ms with plugins and 20‑70 ms without, offers 65 themes, and requires minimal configuration.

Problem

Existing app launchers repeatedly failed to meet the author’s expectations for speed, aesthetics, and cross‑platform consistency, leading to frequent uninstalls.

Outcome

Zenkai delivers a fast (140 ms startup with plugins) and visually appealing launcher across Linux, macOS, and Windows, with extensive theme support and minimal configuration.

Workflow

• 1. Chose Zig for performance and manual memory control.
• 2. Selected Qt6 for cross‑platform GUI and rich styling.
• 3. Implemented core launcher logic in Zig.
• 4. Built theme system using Qt’s QSS and data files.
• 5. Optimized startup to reduce time to 140 ms (plugins) or 20‑70 ms (no‑icons).
• 6. Added 65 themes covering popular color schemes and accessibility options.
• 7. Released binaries for Linux, macOS, and Windows.
• 8. Provided a CLI flag to switch themes without configuration files.

Evidence

I have been obsessed with performance for as long as I can remember.

Source

zenkai --debug --quit-when-shown [zenkai] window fully visible in 140ms

Source

If we run it without plugins and the no-icons flag we get 20-70ms until fully interactive

Source

I chose Zig and Qt6!

Source

There are 65 of them and the reason adding another one is not work. You are not writing a new screen, you are filling in colours.

Source