| Horde_Array | The Horde_Array:: class provides various methods for array manipulation. |
| Horde_Array_Sort_Helper | Helper class for sorting arrays on arbitrary criteria for usort/uasort. |
| Horde_Domhtml | Parse DOM data from HTML strings. |
| Horde_String | Provides static methods for charset and locale safe string manipulation. |
| Horde_String_Transliterate | Provides utility methods used to transliterate a string. |
| Horde_Util | The Horde_Util:: class provides generally useful methods. |
| Horde_Variables | An OO-way to access form variables. |