mtPaint is a simple GTK+1/2 painting program designed for creating icons and pixel based artwork. It can edit indexed palette or 24 bit RGB images and offers basic painting and palette manipulation tools. It also has several other more powerful features such as channels, layers and animation. Due to its simplicity and lack of dependencies it runs well on GNU/Linux, Windows and older PC hardware.
WWW: http://mtpaint.sourceforge.net/