Iconverter was written originally as a developer tool to create ICNS files from anything dropped on it, now it has evolved to support icns, gif, jpg, png, bmp and tiff exporting--and batch conversion. The source code is available.
Version 0.9: I received a lot of interest in this program being made universal. It hasn't been actively developed in half a decade. Because of this interest I am releasing this v0.9 version that includes updated intel compatible libraries and is compiled as a universal binary. I have no intel machine so could not test it, if any issues persist feel free to email me but be forewarned that i do not have much time to devote to this project.
LAXDUDE88888 Great program- simple to use and took up very small amount of space. Did exactly what I wanted to do- create a free, quick Macintosh HD icon from a .jpg on my computer. Thank you so much! (Version 0.9)
THECAUSE Simply insanely great. Now it is extremely simply to take any 128x128 icon with a transparent background and make it into an icon. (like on iconarchive.com) Simple, easy to use and an excellent value. (Version 0.9)