Connotea is an online reference management system. It allows users to store and organise their links and scholarly references online, and can automatically import bibliographic data from online archives. This project hosts the source code for Connotea.
Almost the only open-source online reference/bookmarks-management tool. Being open-source is highly important for the life of the scientific community, which values reproducibility in its work. So it's great that they created it. But it's a pity that: it doesn't get much attention, no site clones appear, and the development has stalled. :(