Display system activity in real-time. In addition to CPU, GPU, VRAM, FPS, disk and network info, atMonitor allows interaction with processes, setting up triggers, logging, purging RAM and more. Three views: menu bar, floating window and top window. Four different themes.
Keep track of all the details of what’s happening with the battery in your portable mac as it happens.
Menu bar item lets you know how much memory you have free at any given time. Click on it to get details on used, total, wired and inactive memory. A utility like this is handy if you’re worried that certain apps are pushing your Mac to its performance limitations.
Create custom desktops with time, date, calendar, the weather, to-do lists, system monitors and more. The catch is that you really do have to be a geek to be able to use GeekTool. Luckily there are plenty of examples and tutorials.
See if you are running low on RAM with a display of your Mac’s memory allocation.
Keep track of what’s going on in your Mac with MenuMeters — a set of of monitors for CPU system load, disk activity, memory and network throughput. The cool thing is that they all sit on your menu bar.