Here are the classes, structs, unions and interfaces with brief descriptions:

NSArray(WIDeepMutableCopying)
NSArray(WIFoundation)
NSData(WIDataChecksum)
NSData(WIFoundation)
NSDate(WIFoundation)
NSDateComponents(WIFoundation)
NSDictionary(WIFoundation)
NSError(WIFoundation)
NSFileManager(WIFoundation)
NSInvocation(WIFoundation)
NSLocale(WIFoundation)
NSMutableArray(WIFoundation)
NSMutableDictionary(WIFoundation)
NSMutableString
NSNetService(WIFoundation)
NSNotificationCenter(WIFoundation)
NSNumber(WIFoundation)
NSObject(WIDeepMutableCopying)
NSObject(WIFoundation)
NSObject(WIObjectPropertylistSerialization)
NSObject(WIThreadScheduling)
NSProcessInfo(WIFoundation)
NSScanner(WIFoundation)
NSSet(WIFoundation)
NSString
NSThread(WIFoundation)
RKLBuffer
RKLCachedRegex
RKLFindAll
UParseError
WIDateFormatter
WIDateFormatter(Private)
WIEventFile
WIEventQueue
WIEventQueue(Private)
WIObject
WIReadWriteLock
<WIReadWriteLocking>
WISettings
WISettings(Private)
WISizeFormatter
WITextFilter
WITimeIntervalFormatter
WIURL
WIURL(Private)