Slate's architecture critic Witold Rybczynski takes a look at the new approaches to designing central city public libraries in an intriguing slideshow essay.

The structures range from Ludwig Mies van der Rohe's trademark-modern Martin Luther King Jr. Library in Washington, D.C. (which has recently been called "an outmoded structure erected long before the advent of the digital world" by a task force appointed by the city's mayor), to 2004's Rem Koolhaas/OMA-designed Seattle Public Library (above), a "giant, multilevel greenhouse...conceived as a drop-in center" that has, according to Rybczynski, the "rough urban chic of a converted loft."