My very first art program was none other than MS Paint, which came pre installed on my father's Windows 7 laptop. I really liked that program because of its Win7 style Aero UI and because it was easy to use. All my old drawings were lost when that laptop broke down, and I hadn’t had a chance to back them up. That laptop lasted 8 or 9 years. And well, my father has already taken some of its parts for other uses.
Nowadays, my main art program is Krita. I draw in it more often than in any other program. Other art programs I use are
VoidSprite (pixel art), Aseprite (pixel art,
I compiled it myself), MyPaint, and an old Japanese art program that Kikiyama (according to some people on the
CoUn Discord server) used for the game Yume Nikki. The program is called
Yumeiro No Enogu (ゆめいろのえのぐ).