Sundance: Directors Maia Lekow and Christopher King commit to capturing the years-long effort to revive three libraries in Kenya after decades of neglect. “How to Build a Library” begins in 2017.

It may not seem unusual that a senior-living community would have a library, but the newest amenity unveiled last week at La Jolla’s Casa de Mañana is different. The “little free library,” which had a ...