Psi

There are many instant messengers that use the XMPP protocol, but they don't offer much when it comes to expanding their functionality. If you want more freedom when chatting with your friends or co-workers, then you should look at Psi. It provides full support for Jabber or XMPP and it comes with numerous features. The main advantage of Psi is the fact that it's open source, so you can do anything you want with it. What's more, you can use this highly customizable application on Mac OS X, Windows or Linux.

When launched for the first time, Psi will provide you with the necessary options for setting up a chat account, on one of many supported servers. Also, you can set up additional accounts later, if you want to. The main user interface has a clean and simple layout. It displays your accounts in a list, along with their corresponding contacts. If you have multiple accounts and you wish to add a contact, you can choose to add it for one account or the other.

New contacts can be defined on a separate window, on which you have to specify a XMPP address and nick name and make a few fine tweaks if you need to. You can chat with a selected contact and send offline messages, with or without attachments, emoticons, and other elements, on separate windows. Furthermore, the application provides full support for voice chat. Besides chatting with individual contacts, you can also discover and join numerous chatrooms, in which you can discuss on various subjects.

Customization is another central feature of Psi. You can change its appearance by applying different colors, icons or emoticons. It is also possible to customize the application's toolbars, keyboard shortcuts and other elements, to make your experience more comfortable. What's more, Psi comes with a XML console, which should give you more freedom, regardless of what you intend to do.