The Lightweight Access Control List is a frame/library to use for login and access control to a website you build.
It uses a basic role bases access control system, that has admin defined actions groups into roles that can be assigned to users.
It is compatible with Facebook’s OAUTH system, and can be used with this.
It can also be used as an API for remote calls authentication calls from another site, which wants to use your site as its authentication system(just as how this system can use facebook).
It is open source, and available under the GNU Affero General Public License.