Redmine

I would like users be able to login/sign-in using either their email address or username, instead of only their username.

Quite often our (less regular) clients have difficulty logging into to our Redmine instance. The most common cause is that they have forgotten, or simple forgotten to use, their username and are instead trying to use their email address.

Allowing people to login using their email address, instead of or as well as their username, is a common practice on many web-sites/applications these days.