Jordi Boggiano has posted about a new feature in Composer, the popular dependency manager for PHP, around the handling of authentication information.
Up until today if you run a home-grown package repository serving private packages it was quite a pain to use with Composer. You did not have efficient way to password-protect the repository except by inlining the password in the composer.json or by typing the username/password every single time. With the merge of PR#1862 and some further improvements you can now remove credentials from your composer.json!
The new functionality allows for the external storage of the credentials in a file, either globally of in one relative to the repository. He also includes the command you can use to configure and set these username/password combinations and have them stored in the "auth.json" file.