# Overview

Smack is a library for client-to-server XMPP connections to perform real-time communications and data exchange. This includes, but is not limited to, instant messaging and group chat. More genericly speaking, it allows you to easily exchange data in various ways: For example fire-and-forget, publish-subscribe, between human and non-human endpoints. The use cases include M2M, IoT, and many more.

Smack is a pure Java library, open-source and highly modular. It runs on Android and Java SE. The API strives to be easy to use but yet powerful.

## Key Advantages

Smack is extremely simple to use. Sending a text message to a user can be accomplished in only a few lines of code.

    AbstractXMPPConnection connection = new XMPPTCPConnection("mtucker", "password", "jabber.org");
    connection.connect().login();

    Message message = connection.getStanzaFactory()
       .buildMessageStanza()
       .to("jsmith@igniterealtime.org")
       .setBody("Howdy! How are you?")
       .build();

    connection.sendStanza(message);

    connection.disconnect();

Smack doesn't force you to code at the protcol level of XMPP. The library provides intelligent higher level constructs, often called {@link org.jivesoftware.smack.Manager}, which let you program more efficiently. Other examples of those constructs are the Chat and Roster classes.

Smack comes with APIs for easy machine-to-machine communication. You can set any number of properties on each message, including properties that are Java objects.

## License

Smack is open-source and most parts are under the Apache License 2.0, which means you can incorporate Smack into your commercial or non-commercial applications. Some parts of Smack may be under a different open-source license. Please refer to the individual subprojects for their license statement.

Note that the Apache License 2.0 requires that the contents of a NOICE text file are shown "…within a display generated by the Derivative Works, if and wherever such third-party notices normally appear.". Smack comes with such a NOTICE file. The content of Smack's NOTICE file can conveniently be retrieved using {@link org.jivesoftware.smack.Smack#getNoticeStream}.

## About XMPP

XMPP (eXtensible Messaging and Presence Protocol) is an open protocol standardized by the Internet Engineering Task Force (IETF) and supported and extended by the XMPP Standards Foundation (XSF).