Language

Office Language Packs

These are additional components that can be installed alongside Office.
These enable users to change the language for menus, toolbars, dialog boxes, help, etc
These are not free
Individual language packs are available for the following languages:
Arabic, Brazilian .. Vietnamese

Language packs for East Asian Languages include: Input Method Editors (IME)
These allow users to input complex characters and symbols using a standard keyboard

You can access the language packs dialog from within Excel
(File > Options)(Popular tab, Language Settings)

2007 Office Language Pack SP2

Language Interface Packs

These provide a set of tools available for the following five applications: Excel, Word, PowerPoint, Outlook and OneNote
They do not contain Help as part of the download package
These are free