Mendeley is a reference management program where you can collect and organize your references and automatically insert citations and create bibliographies. You can collect PDF's, read and annotate in Mendeley.
Through Mendeley you can create groups in order to share references and the program also provides an online academic social network.
Mendeley can be used both online and as a desktop client. Malmö university library doesn't have a campus licens for Mendeley, however you can use the free version of the program and you can also upgrade to a premium version for a fee.