Some of you have heard or even tried these homebrew apps, but for those that are not aware I will post the links to their respective homepages to find out more. Some of these apps are in development process, but do show something on the screen when you try them.
So here is a small list:-
DSLinux: this app ports linux to the nintendo DS system. It currently shows some linux loading code on the upper screen of the DS, while touch keyboard is shown on the lower screen.
WinsDS: this app shows a GUI on both screens and is highly developed. You can drag, write on the notepad, play tic-tac-toe, and there is also a love calvulator.
WindowsDS: this emulates WinXp on the DS, but currently it only shows a splash screen. (Sorry I lost the website for this if anyone knows what it is post in comments pls thank you)
NOTE: I patched these roms with ndsloader.bin to make them work on supercard. If you do not know how to patch them read Here and scroll down to read.