Gimp

GIMP (GNU Image Manipulation Program) is a freely distributed piece of software suitable for such tasks as photo retouching, image composition, and image authoring. It is a powerful piece of software with capabilities not found in any other free so..

This program is capable of converting any popular image format into Microsoft Icon format, plus giving you great control over your conversion process. IconMaster supports all color modes and sizes, alpha-channel, special effects and more...