A nice plasma effect using moiré patterns.
You can watch the animation here:
https://helderman.github.io/moire-plasma-effect/html5/demo.html
Animated using CSS; two patterns of slightly wavy parallel lines continuously sliding across each other.
The patterns are generated by GIMP 2.8.10 using Script-Fu (TinyScheme version 1.40); see the makefile.
Font: Orbitron.
You can watch the animation here:
https://scratch.mit.edu/projects/69153268/
You can find the source code here.