OpenStreetMap now allows accounts to be authenticated with OpenID as
an additional, optional authentication method for some OSM functions.
You may ignore this if you are not interested in OpenID. Some users
find OpenID an interesting way to reduce the number of passwords they
have to use in their travels on the internet.
If you have an existing OpenID or wish to create an OPenID for use
with OpenStreetMap, have a look at the OSM OpenID page on the wiki for important caveats.