There is no obvious mechanism by which one might localize the UI in Fossil.  If I want to have Spanish-speakers (who don't know English well) use the product, I currently need to go through all the menus etc., and manually change them.  This is extremely time-consuming and prone to failure.

I would like to request we use something like GNU gettext (which is very easy to use), and then whoever wants to contribute a localization may do so.  Then, one only needs a way to indicate to Fossil that it should use a specific locale (for example, adding "locale=es" as query parameters).