The Unarchiver - Get the top application for archives on Mac. It's a RAR extractor, it allows you to unzip files, and works with dozens of other formats.

ImBatch - ImBatch is a batch image processor with a nice graphical user interface.

zpaq - Incremental Journaling Backup Utility and Archiver

DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.

FreeArc - FreeArc is a free and open source file archiver developed by Bulat Ziganshin.

Batch Image Resizer - Resize, crop, shrink, flip, exif-rotate, convert, enhance, process multiple pictures and photos with professional software! 120+ Actions, 30+ Image Formats