How's this laser cutting effect with backlight achieved? Sorry for the general question, I don't even know how to tag it:
https://www.youtube.com/watch?v=61UkkpsASwQ

In this video, the effect is such as if there were a laser cutting a shape with a light source behind it, and then the cut is closed again (like some trail effect).
How is this made and with which kind of software/programming? Is 3D involved here or can this be achieved with procedural 2D programming and shaders?
This question may be off-topic here, but this is almost certainly a 2D effect, and it's achievable without much difficulty in After Effects or any similar package once you've broken the effect down into individual elements.
This isn't exactly the same effect, but it gives most of the ideas: https://www.youtube.com/watch?v=uHFmWu__Q4k
The key point here is that you need to look not at the effect as a whole, but break it down into the individual elements that make it up. The parts make the whole.