Nucleo - Commercial vector icons and accompanying apps to manage and customize them.
Icon Generator - Icon Generator is a little application built on AIR that lets you generate a CS5 or Web 2.
Vivid JS - A highly customizable, open source SVG icons library
Icon Slate - Icon Slate lets you easily compose, import and export desktop icons in many formats.
Line Awesome - Same icons as Font Awesome, but in a modern outline style.
IcoFX - IcoFX is an all-in-one solution for icon creation, extraction and editing.