UI, subtitles, synchronization, map editor and map generator. All this translated to English.
- Mjorky's fan translation updated by KonradAr.
There was once this forum post by him from 2010: Link how to install the Vikings AddOn from a DVD, and how to apply the translation.
(There was also a similar post for the French translation on the now removed old Ubisoft forum)
This installer with the fan translation should apply all the translated files automatically.
Also check the Fan Translation for The Settlers: Rise of Cultures.
How to install the Vikings AddOn for The Settlers II: 10th Anniversary?
1) Insert DVD into drive.
2) Select "Select what happens with this disc" from the bottom right corner.
3) Select "Open folder to view files" from the top right corner.
4) Open "setup.exe" with an file archiver like 7zip ("Open archive")
5) Extract the folders \bin, \data, and \dataaddon into the game folder of The Settlers II: 10th Anniversary.
6) Overwrite files if you're asked to do it, and close the File Archiver.
7) Install the Vikings English Fan Translation or the French Fan translation.
8) Install the 2009 Patch.
9) Install the Widescreen Fix, to see more on the field, for monitors wider then 4:3.