This tool finds all pages and categories in a category tree in language X. Then, it checks all of these categories in other languages, and gets pages with a language link back to X there. It lists all pages in X that are not in the original category tree, but in the tree equivalent in other languages.
Category, depth
External depth (>0 gets more pages, but is much slower) Temporarily disabled
(Example: French scientists on fr.wikipedia)

Fatal error: Uncaught Error: Call to undefined function findSubcats() in /data/project/catscan2/public_html/ Stack trace: #0 /data/project/catscan2/public_html/cross_cats.php(99): Pagelist->loadCategoryTree(Array) #1 {main} thrown in /data/project/catscan2/public_html/ on line 321