Greenfish links are down.
IcoFX packs a respectable amount of features for a free software. It can be used to extract and modify icons in .dll and .exe files. Images can be converted to icons in batches and it is also able to save icons in .icns format for Macs. The actual image editing in IcoFX is not as good as in the other 2 icon editors below. The drawing tools do not support smoothing (IcoFX fakes it by drawing a semitransparent outline). A big plus of IcoFX is an integrated file browser and cute pictures in effect window.
While IcoFX is not as powerful as Greenfish IE (not supporting layers or smoothing), it is a polished application that is recommended for beginners looking for an application that would guide them.
Version: 1.6.4
Homepage: http://icofx.ro (latest IcoFX is not free anymore)
GFIE is a surprisingly powerful free icon editor. In addition to icons, it can also edit static and animated cursors and ordinary images in the usual file formats. Greenfish Icon Editor Pro supports layers, image selections (masks) and offers a variety of configurable drawing tools, including brush, rectangle, ellipse, text, flood fill or retouch. All tools support smoothing. The editor has a couple of built-in image effects (incl. bevel, grayscale, glow, or sharpening), which can be applied to entire images or to selected regions.
GFIE may be a bit rough around the edges, but the amount and depth of its features is superior. For expert users, GFIE is the best free choice.
Version 2.1:
Homepage (kind-of, there is no dedicated homepage): http://greenfish.cixx6.com/
Pixelformer is an unusual little beast. It does a lot of things in a non-standard way. It has a custom user interface that ignores visual styles and resolution setting. It uses supersampling instead of ordinary (and usually superior) edge anti-aliasing. There are no filters and .ico files are not opened via the Open command, but via the Import command. On the other hand, there is support for layers and the drawing tool selection is good.
Pixelformer is still in beta (meaning not final, stable version) and has been in beta for a couple of years. But it seems relatively stable and usable. Still, IcoFX or Greenfish are probably better choices.
Version: 0.9.6.3
Homepage: http://www.qualibyte.com/pixelformer/
Greenfish links are down.
Eadstuty
Find out how Vista icons differ from XP icons.
See how RealWorld Icon Editor handles Vista icons.