Two dozen squat robots scurry on the warehouse floor. They park underneath man-high inventory racks and activate a lifting mechanism that jacks the racks off the ground. One robot hauls shelves with 12-packs of Mountain Dew; another carries bottles of Redken shampoo.

They move along straight lines and make 90-degree turns. It's a bit like Pac-Man.

This is the demonstration facility of Kiva Systems, a start-up in Woburn, Mass., just north of Boston, that wants to revolutionize the centuries-old warehouse business. Kiva's idea is simple: by making inventory items come to the warehouse workers rather than vice versa, you can fulfill orders faster.

A central computer keeps track of all robots and racks on the floor, and resource-allocation algorithms efficiently orchestrate their movement.

Today's most automated distribution centers rely on vast mazes of conveyor belts, chutes, and carousels. Human operators stand along the conveyors, near inventory shelves, grabbing products and putting them into boxes or totes rolling past them.

Kiva claims that its system makes it easier to set up and manage a warehouse and that it can boost order-fulfillment speed to three times that of conveyor-based operations.

Since 2004, Kiva has amassed US $18 million in funding from Bain Capital and other investors. It has also signed up three heavyweight customers.

The office supply giant Staples uses more than 500 Kiva robots at its fulfillment center in Chambersburg, Pa., and has equipped an entire warehouse in Denver with the robotic system. Walgreens, the drugstore chain, is using hundreds of Kiva robots at a distribution center in Mt. Vernon, Ill., to prepare cases with inventory to restock stores.

And Zappos, the online shoe store, is adding Kiva robots to part of its massive fulfillment center in Shepherdsville, Ky., which houses 4.2 million shoes, handbags, and clothing items.

IEEE Spectrum visited Kiva early this year to find out how the company created its remarkable robots and how its "warehouse of the future" works.