POOLE, Alastair (netstar)

Free and Open-Source Development/Consultancy/News (Aberdeen, Scotland).

Evisum – System Monitor

Evisum is a graphical system monitor for Linux, macOS, FreeBSD, DragonFlyBSD and OpenBSD. It also includes a command-line utility for querying sensors and resource usage.

As with most open-source projects the majority of the work is done in free time. I’m very keen to add to the existing set of applications developed with EFL for Unix-like desktops.

Effort was made to ensure behaviour is uniform across operating systems. The most strenuous part in development was having enough hardware to test enough configurations for this. Each system has its own API for doing this, also there are bugs in ACPI (circumvented), also some machines have more than one battery unit and it’s necessary to develop on real hardware as virtualised machines tend not to emulate hardware sensors. Therefore the process was protracted and arduous.

There’s an included debugging feature which will monitor per-process statistics and also allows you to send signals to stop, start and kill the process; useful when developing and debugging applications for a GUI.

The plan now is to rewrite the whole program to write sensor information to disk so that Enlightenment and other applications can query statistics over time (as well as “real-time”) and allow us to use nice graphs as well as minimising code re-use.

It’s also an interesting insight into the various APIs each operating system provides for process information, CPU, memory and sensor queries.

The existing user-interface should keep most people happy for now.

The images are self-explanatory. It’s written in C using EFL for the graphical user interface.

You can download evisum 0.2.0 at:


or follow at:


Tingle is included in Evisum, however development is done at:


Enjoy responsibly!

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