Original Link: https://github.com/uzyn/opauth
Authenticating users with well-known providers (like Google, Twitter or Facebook accounts) is widely used and an easy-to-use model for end-users.
However, when it comes to applying the feature, you need to deal with the requirements of each provider.
Opauth is an open source PHP library that removes the inconsistencies between providers and offers a standardized method for dealing with them.
Currently, 3 providers are almost plug ‘n’ play: Google, Twitter + Facebook and there are more to come. Also, there is support for dealing with any other Oauth provider.
Also, it integrates well with existing PHP frameworks pretty easily.