Fledge is a language/shell for processing files (mainly text and image files). A few examples will hopefully explain it better:
with *.text split on /==%==/ to page-%%%.text starting with 1 replace /==%==// trim
with image*.jpg where width > 600 print name, imagesize rotate 90 resize 150w
with **/*.png convert to jpg
Also see related blog posts.
Full installation/configuration instructions are in the README.