Currently, we have quite a mess in src/res: Icons in bmp, png, ico, xpm and "GdkPixbuf RGBA C-Source image dump" format, most of them derived with the help of a graphics program or some uncommon tool from other icons in that directory. The only exception is that the menu icon for Linux is created at install time from the oc.ico, but not using the highest resolution from that file, which wouldn't even be the highest resolution of that icon we have in the resource repository. Now Sven-Hendrik Haase, a packager for Arch Linux wrote a patch to replace that with yet another copy. While I can somewhat understand the desire not to require imagemagic (we probably wouldn't want to inflict it on our poor windows builders), I'd rather see a move in the other direction: Store the icons in just one format in the repository, and create the other formats from that. Or, at least, have a script there that can recreate the icons. (The icons for the editor are slightly more complex because the originals didn't have alpha-channel transparency, but the windows editor really has no valid excuse to still use those.)

Does anybody know how to create the mac icons from script on linux and windows?

Is openclonk-resources/graphics/OCIcon/512.png (or 256.png) the right choice for a higher-resolution Linux menu icon?