With this massive catalogue stored in its servers, the PLOS staff has to be very careful that it’s running a library and not a graveyard for scientific research. It would be easy for papers to be buried in the deluge, irretrievable to anyone who didn’t know the exact authors or titles they were interested in. To make sure researchers can find their way through the PLOS archives, a continuous project is maintained of tagging articles with searchable metadata, and refining the algorithms that match papers to their subject areas.

“It’s all about helping people find what they need to find,” says PLOS’s Rachel Drysdale, “in a way that’s systematic and comprehensive.”