Here are the classes, structs, unions and interfaces with brief descriptions:
  AppendIterator | Iterator that iterates over several iterators one after the other |
| ArrayAccess | Interface to override array access of objects |
| ArrayIterator | An Array iterator |
| ArrayObject | An Array wrapper |
| BadFunctionCallException | Exception thrown when a function call was illegal |
| BadMethodCallException | Exception thrown when a method call was illegal |
| CachingIterator | Cached iteration over another Iterator |
| CachingRecursiveIterator | Compatibility to PHP 5.0 |
| CallbackFilterIterator | A non abstract FiletrIterator that uses a callback foreach element |
| Countable | This Interface allows to hook into the global count() function |
| DbaArray | This implements a DBA Array |
| DbaReader | This implements a DBA Iterator |
| DirectoryFilterDots | A filtered DirectoryIterator |
| DirectoryGraphIterator | A tree iterator that only shows directories |
| DirectoryIterator | Directory iterator |
| DirectoryTree | A directory iterator that does not show ' |
| DirectoryTreeIterator | DirectoryIterator to generate ASCII graphic directory trees |
| DomainException | Exception that denotes a value not in the valid domain was used |
| DualIterator | Synchronous iteration over two iterators |
| EmptyIterator | An empty Iterator |
| Exception | Basic Exception class |
| FilterIterator | Abstract filter for iterators |
| FindFile | Base class to find files |
| InfiniteIterator | An infinite Iterator |
| IniGroups | Class to iterate all groups within an ini file |
| InvalidArgumentException | Exception that denotes invalid arguments were passed |
| Iterator | Basic iterator |
| IteratorAggregate | Interface to create an external Iterator |
| IteratorIterator | Basic Iterator wrapper |
| KeyFilter | Regular expression filter for string iterators |
| LengthException | Exception thrown when a parameter exceeds the allowed length |
| LimitIterator | Limited Iteration over another Iterator |
| LogicException | Exception that represents error in the program logic |
| MultipleIterator | Iterator that iterates over several iterators one after the other |
| NoCvsDirectory | |
| NoRewindIterator | An Iterator wrapper that doesn't call rewind |
| OuterIterator | Interface to access the current inner iteraor of iterator wrappers |
| OutOfBoundsException | Exception thrown when an illegal index was requested |
| OutOfRangeException | Exception thrown when an illegal index was requested |
| OverflowException | Exception thrown to indicate arithmetic/buffer overflow |
| ParentIterator | Iterator to filter parents |
| RangeException | Exception thrown to indicate range errors during program execution |
| RecursiveArrayIterator | A recursive array iterator |
| RecursiveCachingIterator | Cached recursive iteration over another Iterator |
| RecursiveCompareDualIterator | Recursive comparison iterator for a RecursiveDualIterator |
| RecursiveDirectoryIterator | Recursive directory iterator |
| RecursiveDualIterator | Synchronous iteration over two recursive iterators |
| RecursiveFilterIterator | Iterator to filter recursive iterators |
| RecursiveIterator | Interface for recursive iteration with RecursiveIteratorIterator |
| RecursiveIteratorIterator | Iterates through recursive iterators |
| RecursiveRegexIterator | Recursive regular expression filter for iterators |
| RecursiveTreeIterator | RecursiveIteratorIterator to generate ASCII graphic trees for the entries in a RecursiveIterator |
| RegexFindFile | Find files by regular expression |
| RegexIterator | Regular expression filter for iterators |
| RuntimeException | Exception thrown for errors that are only detectable at runtime |
| SearchIterator | Iterator to search for a specific element |
| SeekableIterator | Seekable iterator |
| Serializable | Interface for customized serializing |
| SimpleXMLIterator | Recursive SimpleXML_Element iterator |
| SplDoublyLinkedList | Doubly Linked List |
| SplFileInfo | File info class |
| SplFileObject | Object representation for any stream |
| SplObjectStorage | Object storage |
| SplObserver | Observer of the observer pattern |
| SplQueue | Implementation of a Queue through a DoublyLinkedList |
| SplStack | Implementation of a stack through a DoublyLinkedList |
| SplSubject | Subject to the observer pattern |
| SubClasses | Collects sub classes for given class or interface |
| Traversable | Interface to detect a class is traversable using foreach |
| UnderflowException | Exception thrown to indicate arithmetic/buffer underflow |
 UnexpectedValueException | Exception thrown to indicate an unexpected value |
