The most popular alternative is SageThumbs, which is both free and Open Source. If that doesn't suit you, our users have ranked 4 alternatives to Icaros so hopefully you can find a suitable replacement. Other interesting Icaros alternatives are MysticThumbs (Paid), Instant ThumbView (Paid) and ThumbView (Free, Open Source).
- SageThumbs is a powerful shell extension allowing to preview enormous amount of image formats directly in Windows Explorer by using Pierre-e Gougelet's GFL library...
- MysticThumbs generates thumbnails of many image types not natively supported by Windows.
- Instant ThumbView is a tiny image viewer that displays image thumbnails in a tooltip window, when mouse pointer is hovered over an image file in Windows Explorer.
- ThumbView enables image thumbnails and tooltips in Microsoft Windows XP Explorer (does not work on Windows 7) for filetypes that are not natively supported.