IcoFX - IcoFX is an all-in-one solution for icon creation, extraction and editing.
JDraw - Open Source SF.net
IconLover - Icon editor for Windows.
IconsExtract - Extract icons and cursors stored in EXE, DLL, OCX, CPL files
Pixelformer - A tool for creating, editing, and converting icons and bitmaps.
icoworks - .ico editor for Windows 8 and Windows RT