NTR CFW. I don't actually know what the "NTR" part stands for, if anything, but it's a homebrew app you can use if you have a "New" model 3DS - New 3DS, New 3DS XL, New 2DS XL. NTR CFW lets you stream your 3DS's gameplay feed over WiFi.
The "New" models have a CPU speed of 804 MHz, compared to the original model's 266 MHz. This enhanced processing power gives the app enough power to stream the 3DS's two screens over the internet, while still leaving enough power left for the games you're playing to run the same as they usually do. Now, a consequence (For speedrunning, at least) of using NTR is that load times in games released before 2015, the year the first "New" model came out, are decreased thanks to the increased processing power. Because of this, there's a timing penalty you need to add to your timer, so NTR and non-NTR runners can be on a level playing field.
