Axialis AX-Icons is an excellent icon editor and librarian.

Almost any type of icon can be created with Axialis. The program handles any size icon with any number of colors, and handles multiple-image icons well. There are a variety of editing and painting tools available, including: gradients, lines, rectangles, ellipses, text insertion, mirrors, rotations, color replacement, 3D frame, and fill.

One of the nicest touches is the scaling and color conversion options available when cutting and pasting. This makes it easy to grab an image from almost anywhere and make it part of an icon.

The built-in librarian allows you to extract/import/export icons, save icons in BMP format, manage icons, read and write icon libraries (ICL files), create DLLs, and rename icons within libraries. For distributing an icon collection, you can compile a library into a self-executable EXE file.