Tux Paint 0.9.17 is now available (for Windows, Linux, Mac OS X).

"Tux Paint is a free, award-winning drawing program for children ages 3 to 12 (for example, preschool and K-6 in the US, key stages 1 & 2 in the UK). It combines an easy-to-use interface, fun sound effects, and an encouraging cartoon mascot who guides children as they use the program." [1]

Link: http://www.tuxpaint.org/