ImBatch is described as 'Batch image processor with a nice graphical user interface. It will allow you to edit multiple image files at the click of a button by using scripts. The script will be created by combining Tasks' and is a Image Converter in the photos & graphics category. There are more than 50 alternatives to ImBatch for a variety of platforms, including Windows, Mac, Web-based, Linux and Android apps. The best ImBatch alternative is Image Toolbox, which is both free and Open Source. Other great apps like ImBatch are FastStone Image Viewer, XnView Classic, Caesium Image Compressor and JPEGView.
Approximately the same usability and feature set, but ImBatch spams out-of-memory errors if you open a big folder with big images (still works though), and XnConvert just works without complaining or breaking.