It only took a 107-page specification to complete.
If you’ve ever pressed Ctrl+Shift+Esc to figure out what’s eating away at your PC, you’ve used the work of Dave Plummer. Now, about three decades after writing the original Windows Task Manager at Microsoft, Plummer is back with a new iteration: TMOG. That’s short for Task Manager OG – a variation of the tool he created in 1996 and which was released with Windows NT 4.0 in August.
While taking on X last month, he explained how he (sort of) coded it using Claude Code. Plummer says he gave him a 107-page spec sheet, let the chatbot do its thing, and about four hours later he had a working app that worked the first time. All this while waiting with her hospitalized son, who was recovering from an operation.
The TMOG macOS beta was first released on July 31, followed by the Windows and Linux versions on August 23. The third iteration of the software was released on September 7 alongside early versions of a paid Pro tier.
What TMOG does
TMOG packs 12 views into a single window, covering a summary dashboard, resource usage by process, startup applications, service, power and frequency, network connections, installed applications, disk space and benchmarks.
Status indicators are animated at 60 Hz instead of once per second like with Windows Task Manager, and efficiency cores have their own colors. There are also retro glow-in-the-dark themes, available in green, amber, and blue. Plummer promised that the app “will never provide an answer.”
Look under the hood and you’ll find that each platform runs true native code with Swift and AppKit on macOS, Direct2D on Windows, and Qt 6 on Linux. They all use a shared C++ core. There’s also a self-monitoring option, which adds TMOG’s own process to the readings so you can see what it’s using to operate.
Plummer’s goal with TMOG is to make diagnostics easier. Windows’ built-in tool isn’t always very helpful in helping you figure out why your PC has suddenly slowed down. It is well known that Task Manager lies to you about CPU usage and background processes like Windows Runtime Broker increase resource usage without explanation. TMOG does things differently by displaying the history of the entire machine alongside process activity, making it much easier to track problems back to the culprit in areas like compute or memory.
Built on a freemium model
The free version of TMOG handles live system and process monitoring across all three platforms. Pro adds Flight Recorder, a recording and replay mode that lets you look back on slowdowns as a kind of autopsy to understand why they happened. It costs $39.95 and went on sale at Plummer’s Lemon Squeezy store. It cannot be sold through the App Store because Apple’s sandboxing prohibits apps from listing system processes or removing other programs.
Plummer says the whole project started as an argument over whether anyone could vibrate Microsoft Word code. He didn’t think so, but thought something smaller might work. Given that he is the creator of Task Manager, this is something he knows better than anyone. “You can’t just say to Claude, ‘Hey, write a task manager!’ he wrote about X. “Well you can, but it will be hot trash.”
Instead, he wrote a 107-page spec sheet, comparing it to the work of “some caffeine-fueled PM from the ’90s,” which you wouldn’t really expect from a developer famous for manually optimizing the original down to around 80 KB.
Many cross-platform applications support three operating systems by wrapping a web application in Electron and calling it a day. Deploying code to each platform is quite laborious and expensive, and usually requires a team. Plummer coded his in less than six weeks with two collaborators and Claude Code doing the heavy lifting. You can bash ambiance coding all you want, but you can’t argue that it doesn’t change the economics of a project like this.
For now, it’s in beta, and Plummer says early adopters are still discovering bugs that he needs to iron out. However, the free version does not expire and you can download it now for macOS, Windows and Linux without creating an account.
