| Nonzas | [XEP-0360](http://xmpp.org/extensions/xep-0360.html) | Defines the term "Nonza", describing every top level stream element that is not a Stanza. |
| [Stream Management](streammanagement.md) | [XEP-0198](http://xmpp.org/extensions/xep-0198.html) | Allows active management of an XML Stream between two XMPP entities (stanza acknowledgement, stream resumption). |
| Last Activity | [XEP-0012](http://xmpp.org/extensions/xep-0012.html) | Communicating information about the last activity associated with an XMPP entity. |
| Flexible Offline Message Retrieval | [XEP-0013](http://xmpp.org/extensions/xep-0013.html) | Extension for flexible, POP3-like handling of offline messages. |
| Extended Stanza Addressing | [XEP-0033](http://xmpp.org/extensions/xep-0033.html) | Allows to include headers in stanzas in order to specifiy multiple recipients or sub-addresses. |
| [Multi User Chat](muc.md) | [XEP-0045](http://xmpp.org/extensions/xep-0045.html) | Allows configuration of, participation in, and administration of individual text-based conference rooms. |
| In-Band Bytestreams | [XEP-0047](http://xmpp.org/extensions/xep-0047.html) | Enables any two entities to establish a one-to-one bytestream between themselves using plain XMPP. |
| Bookmarks | [XEP-0048](http://xmpp.org/extensions/xep-0048.html) | Bookmarks, for e.g. MUC and web pages. |
| User Location | [XEP-0080](http://xmpp.org/extensions/xep-0080.html) | Enabled communicating information about the current geographical or physical location of an entity. |
| Data Forms Validation | [XEP-0122](http://xmpp.org/extensions/xep-0122.html) | Enables an application to specify additional validation guidelines . |
| Personal Eventing Protocol | [XEP-0163](http://xmpp.org/extensions/xep-0163.html) | Using the XMPP publish-subscribe protocol to broadcast state change events associated with an XMPP account. |
| Message Delivery Receipts | [XEP-0184](http://xmpp.org/extensions/xep-0184.html) | Extension for message delivery receipts. The sender can request notification that the message has been delivered. |
| XMPP Ping | [XEP-0199](http://xmpp.org/extensions/xep-0199.html) | Sending application-level pings over XML streams.
| Entity Time | [XEP-0202](http://xmpp.org/extensions/xep-0202.html) | Allows entities to communicate their local time |
| Delayed Delivery | [XEP-0203](http://xmpp.org/extensions/xep-0203.html) | Extension for communicating the fact that an XML stanza has been delivered with a delay. |
| XMPP Over BOSH | [XEP-0206](http://xmpp.org/extensions/xep-0206.html) | Use Bidirectional-streams Over Synchronous HTTP (BOSH) to transport XMPP stanzas. |
| Message Carbons | [XEP-0280](http://xmpp.org/extensions/xep-0280.html) | Keep all IM clients for a user engaged in a conversation, by carbon-copy outbound messages to all interested resources.
| [HTTP over XMPP transport](hoxt.md) | [XEP-0332](http://xmpp.org/extensions/xep-0332.html) | Allows to transport HTTP communication over XMPP peer-to-peer networks. |