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.
Wikipedia.
Category, depth
External depth (>0 gets more pages, but is much slower) Temporarily disabled
(Example: French scientists on fr.wikipedia)

( ! ) Fatal error: Call to undefined function findSubcats() in /data/project/catscan2/public_html/omniscan.inc on line 321
Call Stack
#TimeMemoryFunctionLocation
10.000630838184{main}( )../cross_cats.php:0
20.987032213992Pagelist->loadCategoryTree( )../cross_cats.php:99