Activity Monitor is free and already on your Mac. Here is what Stackyard adds

Every Mac comes with Activity Monitor, and it is a good tool. So the fair question about Stackyard is: why would a developer want something else? This post answers it honestly, including the things Activity Monitor still does better.

What Activity Monitor does well

Activity Monitor shows every process on the Mac, including the system's own, with CPU, memory, energy, disk and network tabs. Double-click a process and you can see its parent, its open files and ports, and take a sample of what it is doing. For investigating one misbehaving process in depth, nothing on the Mac beats it, and it is already installed.

If that is the kind of question you have, use Activity Monitor. Stackyard does not try to replace the inspector.

Where it stops being quick

The questions developers ask most days are not about one process. They are about apps, ports and projects, and Activity Monitor answers those slowly or not at all.

"What is using my memory?" Activity Monitor gives you a list of processes. A browser is dozens of them, an editor is a dozen more with its language servers and extension hosts, and adding them up is your job. Stackyard's Memory section folds each app's helpers under it, so the browser is one row with one number, next to Quit and Force Quit.

"Which of these node processes can I kill?" In Activity Monitor they all look the same. Stackyard's Orphans filter lists only the dev processes whose terminal, editor or AI agent has closed, and for each one shows which tool started it (Terminal, VS Code, Cursor, Claude Code, iTerm2, Warp or tmux), the folder it was started in and its PID. The orphans post goes into how.

"What is on port 3000?" Activity Monitor can show a process's open ports once you know which process to look at. Stackyard's Localhost section starts from the other end: every listening port, with a dot that says whether it is answering. Green for an HTTP server responding normally, red for a server error or no answer, blue for something that is not a web server, such as Postgres. Ports opened by Docker carry the container's name. The local servers post covers this section and Share on LAN.

"Start the API, then the front end." Activity Monitor watches processes; it cannot start one. Stackyard's Projects section finds the dev and start scripts in your folders, starts them with a live log, and warns you before a port clash.

"What was using memory an hour ago?" Activity Monitor shows the present. Stackyard records memory every 30 seconds and keeps 24 hours, in total and by app, with the peak and the heaviest app marked.

Things Activity Monitor does not attempt

Some of what Stackyard does has no equivalent in Activity Monitor at all:

• Docker containers grouped by Compose project, with Start All and Stop All, and on/off switches for Homebrew services.
• Measuring and clearing the caches and build folders your tools rebuild on their own, into the Trash.
• Guard: a notification when memory pressure stays high, leak detection, orphans quit on a timer, and Meeting Mode.
• A menu-bar item that shows memory in use and warns when pressure is high, with the heaviest apps one click away.

⌘K, which is the real difference

The biggest practical difference is speed. In Activity Monitor, quitting a process is find it, select it, press the stop button, confirm. In Stackyard, it is ⌘K, a few letters of the app's name, Return.

The same palette opens or stops any local server, starts or stops any project or container, cleans any cache and jumps to any section. Elsewhere in the window, ⌘1 to ⌘9 switch sections, the arrow keys move the selection and Space starts or stops the selected item. And open "stackyard://palette" from Terminal opens the palette from a script.

What Stackyard will not do

Stackyard only quits processes that belong to you. Anything owned by macOS or another user is folded into a single read-only row, System & other users, so you can see what it takes but cannot end it from Stackyard. If you genuinely need to end a system process, that is a job for Activity Monitor and an administrator password, and it should feel like a deliberate act.

Use both

Keep Activity Monitor for the deep dive into one process. Use Stackyard for the ten times a day you want to know what is eating memory, what is on a port, or which node process is safe to quit. Stackyard is a free preview: ask for a build, and the user guide has every shortcut.