A series of high level utilities that perform functions you might generally use scripts for. It is meant to make certain types of operations easy to perform.
A file utility that removes files with the same name but different extensions. As an example:
> ls ./
f1.jpg f1.raw f2.cr2 f3.txt
> wrm -t raw cr2 -s jpg jpeg png
> ls ./
f1.jpg f1.raw f3.txt
The f2.cr2 file ended up getting removed.
This will remove any .raw or .cr2 file that does not have a corresponding .jpg, .jpeg, or .png file of the same name.
For my use case, it's useful for cleaning up undesirable photos after manually reviewing photos. It can be for any filetype though, I have run into this problem when documenting results in experiments and keeping all the different files that document specimen or experiment under the same name is common.