Every year, Congress renews a series of tax breaks for individuals and specific industries, making temporary features of the tax code into a seemingly permanent fixture.
The design featured a wooden frame on top of a concrete-slab foundation, with an exterior covered in gray asbestos shingles. (Steel was in short supply.) The structure violated the Cambridge fire code, but it was granted an exemption because of its temporary status.
Google and Yahoo engineers publish software code for public consumption--a way to access their maps, say, or a temporary link to their search tool--and in a near-instant developers around the globe are building new software based on it.