| EventLog | Helper class to simplify writing to the Windows Event Log |
| Service | Helper class to encapsulate and simplify the process of creating and managing a Windows Service |
| xplComms | Base class for communications objects |
| xplConfigItem | Represents a variable whose value can be edited in xPLHal |
| xplDevice | Implements the core xPL functionality |
| xplFilter | Implements filtering of xPL messages |
| xplMsg | Represents an xPL message |
| xplMsgItem | Represents name=value pairs in an xPL message body |
| xplRef | Provides reference counting for xPL objects |
| xplUDP | XPL communications over a LAN or the Internet |