Swift foundation framework

The foundation framework comprises features outside of the language and runtime that are common to all applications. The base layer of functionality provided in the foundation framework includes data storage and persistence, string handling, data formatting, date and time support, sorting and filtering, and networking. The design principle for the foundation framework is to keep the features in small sets of utility class, consistent across in convention, and with internationalization and localization support. As such, the foundation framework is highly portable for cross-platform support. There are two foundation frameworks: Objective-C and the open source Swift foundation.