You might try, on hardware or emulation: Poco (modern macOS), Blue Paint (classic Macintosh), NewtPaint (Newton), MoePaint (Palm), CHEESE 2 (MSX), Airbrush (PC-

You might try, on hardware or emulation: Poco (modern macOS), Blue Paint (classic Macintosh), NewtPaint (Newton), MoePaint (Palm), CHEESE 2 (MSX), Airbrush (PC-100), Ink Pot (PC-88), ESQUISSE, Multi Paint System, Z's STAFF (PC-98), GraphicsGale, Easy Paint Tool SAI (Windows 9x to current), JINZO Paint (Windows CE, I picked this up recently to added fixes and new features), Matier, Full Color Paint Tool SAI, G-TOOL (X68000)