diff --git a/.tmux b/.tmux
new file mode 100755
index 0000000..8b5f249
--- /dev/null
+++ b/.tmux
@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+# Based on https://github.com/opdavies/dotfiles/blob/main/bin/t.
+
+set -o errexit
+set -o nounset
+
+session_name="${1:-atdc}"
+session_path="${2:-$(pwd)}"
+
+if tmux has-session -t="${session_name}" 2> /dev/null; then
+  tmux attach -t "${session_name}"
+  exit
+fi
+
+tmux new-session -d -s "${session_name}" -n vim -c "${session_path}"
+
+# 1. Main window: Vim, server, shell
+tmux send-keys -t "${session_name}:vim" "nvim +GoToFile" Enter
+tmux split-pane -t "${session_name}:vim" -h -c "${session_path}" -p 40
+tmux send-keys -t "${session_name}:vim.right" "php -S 0.0.0.0:8000 -t web" Enter
+
+# 2. General shell use.
+tmux new-window -t "${session_name}" -c "${session_path}"
+
+tmux switch-client -t "${session_name}:vim.left" ||
+  tmux attach -t "${session_name}:vim.left"