wtf is mac-performance-monitor?

Mac Performance Monitor is a native macOS app that sits in your menu bar and keeps a continuous record of how your computer is running. It tracks CPU usage, memory pressure, GPU load, network activity, disk activity, battery status, and the resource use of individual processes, saving all of it to a local database so you can look back at trends over time instead of just seeing a snapshot. From the menu bar you get a compact, configurable readout of the key numbers, with a shared detail panel you can open for more depth. The main dashboard turns the raw numbers into a plain language verdict about how the machine is doing, along with headline tiles, a pressure timeline you can zoom into, a breakdown of memory use, and a view of swap activity. A process explorer lets you sort and filter every running process and inspect details like memory footprint, CPU use, open file descriptors, disk input and output, and whether a process is running under Rosetta translation. Related apps and their helper processes can be grouped together so you can see their combined impact as a single unit. The app also watches for slow memory leaks, flagging processes whose memory use keeps climbing over time, and keeps a log of pressure events. A deep dive diagnostics feature explains what a given process actually is and whether its behavior looks normal, using signed check packs that can be updated. There are also quiet, off by default alerts for things like critical memory pressure, sustained swap use, and processes that cross memory limits you set. The tool is free and open source, with no telemetry or analytics of any kind, and every sample it collects stays in a local SQLite database on your own Mac. You can install a signed and notarized package from the releases page, or build it yourself from source using Swift, though that requires macOS 15 or later, a Swift 6 toolchain, and an Apple silicon Mac. It ships under the MIT license, a permissive license that lets you reuse and modify the code freely, and it bundles two other MIT licensed libraries for its database and auto update features.