MenuMeters is a set of system monitoring tools for your Mac. As the name suggests, it uses different meters to show you the state of different aspects of your system to you. All the information is shown on the menubar, at the top of the screen. After you install the application, you have to go to the system preferences to enable the meters and to choose which ones you want to see and how you want to display them.
The application's settings are displayed in four different categories: CPU, Disk, Memory and Network. At the top of each one of those screens, you will see a check box that reads "Display menu meter". That is the first step. Next to it will be a drop-down menu that asks how you want to display the information. Thus, you will see options to show only a graph, only arrows, only percentages, or combinations of them, or all of them.
I activated all the meters that were available, and chose to show everything that could be shown. And the space in my menubar was almost gone. It took nearly 30 or 40% of my menubar. From there, though, I can easily see what the temperature of the CPU is, the state of my network and its throughput, both in KB/s and in a neat graphic, memory usage, and disk stats.
All in all, this is a nice free tool to keep you always informed of what is going on. It is a free tool, and you should consider donating if it makes your life easier.
Monitors your system and signals what does not function well.
Very small, open-source system utility.
Application that allows you to boost your Mac memory.
App that allows you to view your room's temperature.
Write Processing sketches in Python.