Resource Filter is described as 'Those who build Programs or Desktop-Themes will never have enough Glyphs and Icons. So why not starting an own creation. You may look in the resource section of the EXE, DLL and other files on your hard disk to look for this stuff'. There are more than 10 alternatives to Resource Filter for Windows, Linux, Online / Web-based and Mac. The best alternative is IcoFX. It's not free, so if you're looking for a free alternative, you could try IconsExtract or Thumbico. Other great apps like Resource Filter are IconLover (Paid), Quick Any2Ico (Free), Icon Explorer (Free) and Batch Icon Extractor (Free).
GConvert icon toolkit: create, edit, extract, manage and convert icons of any size and color depth. Full support for Windows Vista and XP icons, manage icons in ICL and DLL files, convert from/to other image formats