Minecart quantum stockpiles are the most amazing things ever, especially after I had gone through the effort of learning how to get the old hatch/bridge ones working.
As for a less well known technology... uh... not sure if it counts, but I think I invented a bloodcano accidentally?
I was playing in a really nice looking spot, except the gobs were refusing to show up, by the second year I had been busy updating the military gearing, getting artifact micromanagement down better, and decided to set up a trauma chamber to clear out the billion crundles and whatnot I ended up with after I opened the caverns and set up cage traps at various chokepoints.
I had originally built a big drop shaft going through all the main rooms, and decided to set up fortifications around them and repurpose the drop shaft into a waterfall/mist-generator as well.
To keep the drop/disposal capabilities I have a drawbridge under the impact hatch so I can have both open and let water pour through, giving nice thoughts from the mist, or I can close them and splatter stuff, then let the chunks drop into the caverns right?
Well, my first try after getting the waterfall additions done (note that I originally had the bottom bridge set up as an atomsmasher, so it is linked to the same lever as the hatch) had uh... unexpected amazing results.
The room after dropping all the crundles, something like 30 of them:
Naturally it's a mess.
The fall was long enough that chunks actually made it a couple levels up:
So I'm like "ok, I'll drop the trolls/reachers/rutherers/possibly-elk-birds-if-they-don't-fly later, time to clean up", and I have them pull the hatch lever.
The results were... unexpectedly fantastic.
Z+0:
Z+1:
Z+2:
Z+3:
Z+4:
Z+almost all the way up to the waterfall:
The actual waterfall, one level above that picture^:
Yes, a volcano of bodyparts and gore, erupting upwards through multiple levels of living area, is not what I intended, or expected, but I will chalk it up as "happy accident", though it did injure a couple of dwarves when I was trying to figure out what happened and closed the hatch again:
The two flashing dorfs to the right were clunked by corpseparts >.>, but they calmed down once I got the mist going again:
"Suffered injuries recently. Was comforted by a lovely waterfall recently."
I did unlink the bridge so it is on a different lever now, because while it was awesome, and I giggled for half an hour every time I thought about it, I don't need a legendary hammerdorf killed by flying bodyparts during another bloodcano.