This tool takes two lists on a wiki, and adds to list #1 the new entries from list #2. Entries that are in both lists will remain as given in list #1.

Project
Language
Page 1 The page that is the base list, and to which new entries on page 2 are added.
Page 2 The page that contains a list with potentially new entries.
Remove entries that are in list 1 but not in list 2.