IcoFX - IcoFX is an all-in-one solution for icon creation, extraction and editing.
Icon Slate - Icon Slate lets you easily compose, import and export desktop icons in many formats.
RealWorld Icon Editor - Create Windows icons and Mac OS icons from images and 3D models in an integrated icon maker.
Icon Generator - Icon Generator is a little application built on AIR that lets you generate a CS5 or Web 2.
Icon Editor by RedKetchup - View and edit Windows icons (ICO files) directly from the browser. Create icons in 8-bit, 24-bit, or 32-bit color depth. Extract all the layers of an ICO file as PNG images.
Symbols for Sketch - A set of templates to make an icon font with Sketch (gulp)