There's lots of translation work to do for the OpenStreetMap project, both by translating the map data itself by giving names to objects on the map in multiple languages and by translating programs related to OpenStreetMap. E.g. the OpenStreetMap website and various editors.
Contributions are invited from anyone who is able to provide full or partial translations. Sometimes development of internationalization support will be needed first.
This page is for listing the various places where translation efforts are being coordinated.
OpenStreetMap map data
Any object in the OpenStreetMap map data that has a name should be given a name=* tag. But translators can also add additional name tags for other languages, see Names#Localization for documentation on name tags with language prefixes, and take a look at this node for Vienna as an example.
This data permits map internationalization, renderings of the map for different languages and also it's useful data for searches to match on.
Unfortunately there are currently no friendly editors for OpenStreetMap data dedicated to just presenting a translation interface and not allowing other edits. But users can use existing editors in the meantime. To translate e.g. the names of all world capitals one could get all the objects tagged with place=city and capital=yes from the XAPI. Open that data in JOSM and start translating & uploading objects. Ævar blogged about doing this for icelandic names of all capital cities.
Maps powered by OpenMapTiles, Planetiler, or Mapbox label places and other points of interest based on labels of Wikidata items, only falling back to OSM's name=* key if a wikidata=* tag is missing or the Wikidata item lacks a label in a given language. 
OpenStreetMap website interface
OpenStreetMap Foundation Social Networks
Since the wiki holds a lot of important help content and documentation, we try to translate it in as many languages as possible so that anyone can contribute to the project with the same knowledge. Translation is taking place on a somewhat ad-hoc basis. We are currently waiting on the Translate extension to be implemented on the wiki.
Editors and other contributing tools
Analysis and quality assurance tools
- Overpass turbo at Transifex
- QuickOSM at Transifex
- Osmose at Transifex
- Keep Right at Launchpad
- CheckAutopista at Transifex
- NotesReview at POEditor
- Sophox (based on Wikidata Query Service) at Translatewiki.net
- Public Transport Network Analysis at Transifex
Renderers and mashups
- Historical Objects
- Mapbox Android Demo at Transifex
- Mapbox GL (Mapbox Android, iOS, macOS SDKs) at Transifex
- uMap at Transifex
- Wheelmap in several projects at Transifex
- OpenStreetBrowser has its own instance of weblate
- MyOSMatic as a fork of MapOSMatic also has its own instance of weblate and currently not accepting registration.
- Sample driving instructions (a common resource)
- GraphHopper in a Google Sheets spreadsheet
- Mapbox Navigation SDK for Android at Transifex
- Mapbox Navigation SDK for iOS at Transifex
- Navit via Launchpad
- Organic Maps on GitHub
- OsmAnd at Weblate
- OSRM Text Instructions at Transifex
- Valhalla at Transifex
- MapFactor Navigator via crowdin.com
Online translation platforms
You can also search these online translation platforms for more OSM-related tools to translate: