boo: screen, rebuilt on Ghostty (2026)

For the June 27-28 pick, boo is the practical test: a GNU screen-style terminal multiplexer from Coder that keeps the old "session plus prefix key" model, but replaces the terminal-state layer with libghostty-vt, the VT core from Ghostty. The repository has 709 stars, 20 forks, and 4 watchers in the current snapshot. 1

The short version: try boo if you like screen because it is simple, but you want modern terminal redraws and scriptable session control. Skip it if you need tmux-style panes, shared attachments, or a mature multiplexer with years of production mileage. 1

Install

The fastest path on Linux or macOS is the project installer. It downloads the matching prebuilt release asset for x86_64 or aarch64 on Linux or macOS, then installs boo into /usr/local/bin when writable or ~/.local/bin otherwise. 2

curl -fsSL https://raw.githubusercontent.com/coder/boo/main/install.sh | sh

If you want a pinned install, set BOO_VERSION; if you want a different destination, set BOO_INSTALL_DIR. The project also publishes prebuilt binaries on GitHub Releases and lists v0.6.3 as the latest release. 3

BOO_VERSION=0.6.3 BOO_INSTALL_DIR="$HOME/.local/bin" \
  sh -c 'curl -fsSL https://raw.githubusercontent.com/coder/boo/main/install.sh | sh'

Nix users have a direct path through the repository flake, while source builds require Zig 0.15.2. 4 1

# Nix
nix build github:coder/boo
nix develop github:coder/boo

# Source build after cloning
zig build

Use the release installer or Nix/source build for now. Homebrew's formula page for boo did not provide an installable formula, and the project is Zig-based rather than a Rust or Node package. 5 1

What you get in two minutes

boo new starts a session attached to your shell, boo new work creates a named session, boo new work -d -- make starts a detached session running a command, and boo attach work brings it back. The default prefix is Ctrl-a; Ctrl-a d detaches. 1

boo new work -d -- make
boo attach work
# detach inside the session with Ctrl-a d
boo ls
boo kill work

That makes boo feel closer to screen than tmux. It is about durable sessions first, not building a full terminal workspace with splits, tabs, and elaborate layouts.

The interesting extra is automation. The README documents send, peek, wait, and JSON output, all usable without a TTY. A CI-ish local workflow can create a headless session, send make, wait until output is idle, read the scrollback, and then kill the session. 1

boo new build -d -- bash
boo send build --text 'make' --enter
boo wait build --idle
boo peek build --scrollback
boo kill build

That is the real power-user use case. If you run terminal-heavy build, test, or agent workflows and want to inspect a persistent process after disconnecting, boo gives you a small command surface instead of asking you to script around a full multiplexer UI.

Why libghostty matters

The author's Hacker News explanation is the clearest pitch. Kyle Carberry wrote that screen parses output through its own terminal emulator, but that emulator is old enough to mishandle modern escape sequences on redraw. In his words, boo swaps that layer for libghostty-vt, "so the saved state matches what your terminal would actually display." 6

That does not make boo a universal tmux replacement. It makes the project narrower: keep screen's small mental model, improve redraw fidelity, and expose enough commands for automation. The repository tagline says the same thing more tersely: boo is a GNU screen-style terminal multiplexer built on libghostty-vt, written mostly in Zig. 1

Momentum and maintenance

The star curve is young but real. boo started from 0 stars on June 11, reached about 400 by June 15, then slowed to 709 by June 28; the 7-day gain is about 100 stars, from roughly 600 to 709. 7

The release cadence also looks active. v0.6.3 was published on June 26, 2026, and the repository shows 38 releases and 81 commits. That release pinned a macOS runner to avoid a macOS 26 SDK link failure, forwarded application OSC 52 clipboard writes through the boo UI, and bumped the release version. 3 1

Community proof is still concentrated in one place. The Show HN thread from June 11 has 95 points and 28 comments. 8

Caveats before you switch

boo is young, and its own documented limits matter for daily use. Only one client can be attached to a session; attaching steals the session from the existing connected client. Each session has one window, so there are no splits or tabs inside a session. The Ctrl-a prefix is not currently configurable, and all sessions run with TERM=xterm-256color. 1

There is also a macOS caution. One Hacker News commenter reported installing with the curl-to-shell command on macOS Sequoia and then seeing error: ReadOnlyFileSystem when running boo new. That is one public bug report in the collected community material, not a broad failure pattern, but it is enough to make a quick test safer than an immediate workstation-wide switch. 9

The license is straightforward: boo is MIT-licensed, with copyright attributed to Coder Technologies Inc. for 2026. 10

Adopt / try / skip

Adopt if you already use screen-style detached sessions and want better modern-terminal redraw behavior plus CLI automation commands such as send, wait, and peek. 1

Try if you run long local builds, test loops, or coding-agent sessions and want to reconnect later without carrying a full tmux layout model.

Skip if panes, tabs, multi-client sharing, configurable prefix behavior, or a battle-tested ecosystem are required. boo looks promising because it is focused, but that focus is also the boundary.

boo: screen, rebuilt on Ghostty