| DTime | Encapsulates system time |
| Packable | An interface for all packable classes |
| POAddress | |
| POBox |
|
| POBoxIF |
|
| POBoxListMsg | |
| POClient | |
| PODouble | |
| POErrorMsg | A simple text message |
| POFloat | |
| POGroup | Provides a mailing list where every message sent to the group is sent to all members except the member who initially sent the message |
| POGroupMsg | Used to communicate group commands |
| POInt | |
| POMessage | The base class for all messages sent through the PostOffice |
| POMessageFactory | |
| POPartialMsg | Can only be used internally to send large messages in many parts |
| POServer | |
| POSmallFileMsg | |
| PostOffice | |
| POString | |
| POTextMsg | A simple text message |
| Tracer |
1.3.4