According to: https://emulation.gametechwiki.com/index.php/Nintendo_64_emulators

One of the biggest hurdles to emulating the Nintendo 64 was the Reality Display Processor (RDP), which used a custom design that had to be fine-tuned to get higher performance out of the system using microcode. To emulate the RDP accurately, one would have to execute said microcode the way the RDP did, which differed from the PC graphics cards of the day. To complicate matters further, API standards available on PCs two decades ago were nowhere near as flexible as they’re today. If you wanted to make an accurate GPU-accelerated RDP plugin in 2003, you simply couldn’t with the APIs of the time (OpenGL 1.x and Direct3D 9).

Accurate low-level emulation would only come to the GPU in 2020 when a new version of the Mupen64Plus-based ParaLLEl libretro core was released containing a rewritten RDP plugin using compute shaders in Vulkan.

I had to look it up, it’s the technical term for a certain firefighting vehicle.

In particular, what distinguishes it from a normal crew firefighting vehicle (Löschgruppenfahrzeug) is its equipment for “Technische Hilfeleistung” (technical help-providing) which basically means it carries equipment beyond basic extinguishing agents. If you’re physically stuck in your car after a crash, a Hilfeleistungslöschgruppenfahrzeug has to arrive to cut open the doors.

A Hilfeleistungslöschgruppenfahrzeug

A (small) Löschgruppenfahrzeug. Note that it only contains firefighting equipment.