This is a project that I haven't worked on in a long time. I'm currently pulling back together the resources that made this go. Apparently, it became popular while I wasn't paying attention. :)
XNetStrength (or XNetworkStrength) is a tool that I originally wrote back in late 2000/early 2001. It uses only the X11 libraries to do its graphical processing, and is written in C. It's a very fast, very small application that does one thing, and I think, one thing well.
If you find this project useful, and want to support it, I accept donations.
More to come ...
I'm pleased to make this software available again to those who would like to use it. It's been too long since it became unavailable, and I'm glad to change that.
I'm planning on writing one here, but it's only vapor-wear right now.
If you get errors building it that look like this:
$ make gcc -c xns_main.c xns_main.c:7:22: error: X11/Xlib.h: No such file or directory xns_main.c:8:23: error: X11/Xutil.h: No such file or directory
Then almost certainly the X11 development libraries arn't installed. On debian or ubuntu, this can be fixed by installing the xorg-dev package. Other systems should consult their package manager software.
On Debian/Ubuntu:
apt-get install xorg-dev