Applications
GCD is used throughout OS X (beginning with 10.6 Snow Leopard), and Apple has encouraged its adoption by OS X application developers. FreeBSD developer Robert Watson announced the first adaptation of a major open source application, the Apache HTTP Server, to use GCD via the Apache GCD MPM (Multi-Processing Module) on May 11, 2010, in order to illustrate the programming model and how to integrate GCD into existing, large-scale multi-threaded, applications. His announcement observed that the GCD MPM had ⅓–½ the number of lines as other threaded MPMs.
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