Psi is a free

instant messaging Instant messaging (IM) technology is a type of online chat allowing real-time text transmission over the Internet or another computer network. Messages are typically transmitted between two or more parties, when each user inputs text and trigge ...

client Client(s) or The Client may refer to: * Client (business) * Client (computing), hardware or software that accesses a remote service on another computer * Customer or client, a recipient of goods or services in return for monetary or other valuabl ...

for the

XMPP Extensible Messaging and Presence Protocol (XMPP, originally named Jabber) is an open communication protocol designed for instant messaging (IM), presence information, and contact list maintenance. Based on XML (Extensible Markup Language), i ...

protocol (including such services as Google Talk) which uses the Qt toolkit. It runs on

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...

(and other

Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...

operating systems),

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ser ...

macOS macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...

and

OS/2 OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 r ...

tp://ftp.netlabs.org/pub/qtapps/psi.zip Psi build for OS/2 Version 0.15, ZIP package. (including

eComStation eComStation or eCS is an operating system based on OS/2 Warp for the 32-bit x86 architecture. It was originally developed by Serenity Systems and Mensys BV under license from IBM. It includes additional applications, and support for new hard ...

and ArcaOS). User interface of program is very flexible in customization. For example, there are "multi windows" and "all in one" modes, support of different iconsets and themes. Ready-to-install deb and

RPM Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...

packages are available for many Linux distributions. Successful ports of Psi were reported for

Haiku is a type of short form poetry originally from Japan. Traditional Japanese haiku consist of three phrases that contain a ''kireji'', or "cutting word", 17 '' on'' (phonetic units similar to syllables) in a 5, 7, 5 pattern, and a ''kigo'', or s ...

, FreeBSD and

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

Solaris operating systems. Due to Psi's free/open-source nature, several forks have appeared, which occasionally contain features that may appear in future official Psi versions.

Project name

'Psi' is the twenty-third letter of the

Greek alphabet The Greek alphabet has been used to write the Greek language since the late 9th or early 8th century BCE. It is derived from the earlier Phoenician alphabet, and was the earliest known alphabetic script to have distinct letters for vowels as w ...

(Ψ), which is used as the software's logo.

Mission statement

The goal of the Psi project is to create a powerful, yet easy-to-use XMPP client that tries to strictly adhere to the XMPP drafts and XMPP XEPs. This means that in most cases, Psi will not implement a feature unless there is an accepted standard for it in the XMPP community. Doing so ensures that Psi will be compatible, stable, and predictable.

History

The application was created by Justin Karneges and it began as a side project. At various points during its existence Karneges was paid to develop the codebase, during which Psi flourished. Typically however, the release cycle of Psi is relatively slow, but the client has always been seen by its fans as a very stable and powerful instant messaging client. Karneges left the project in late 2004 to pursue other endeavors. In 2002 Michail Pishchagin started hacking Qt code which later became libpsi library. Pishchagin joined the team in March 2003 and he is responsible for many large chunks in Psi code. In November 2004, maintenance was taken over by Kevin Smith, a long-time contributor to the project. In 2009, Smith handed maintenance back to Karneges, who also maintains Iris, the Qt/

C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...

XMPP library upon which Psi is based. Remko Tronçon started writing his custom patches for Psi in 2003, and became an official developer in May 2005. In 2009 a Psi

fork In cutlery or kitchenware, a fork (from la, furca 'pitchfork') is a utensil, now usually made of metal, whose long handle terminates in a head that branches into several narrow and often slightly curved tine (structural), tines with which one ...

name
Psi+
was started. Project purposes are: implementation of new features, writing of patches and plugins for transferring them to upstream. As of 2017 all active Psi+ developers have become official Psi developers, and now Psi+ is just a development branch of Psi with

rolling release Rolling release, also known as rolling update or continuous delivery, is a concept in software development of frequently delivering updates to applications. This is in contrast to a ''standard'' or '' point release'' development model which uses s ...

development model. Users who wants to receive new features and bug fixes very quickly may use Psi+ on daily basis. Users who do not care about new trends and prefer constancy may choose Psi as it uses classical development model and its releases are quite rare.

Features

Because XMPP allows gateways to other services, which many servers support, it can also connect to

Yahoo! Yahoo! (, styled yahoo''!'' in its logo) is an American web services provider. It is headquartered in Sunnyvale, California and operated by the namesake company Yahoo Inc., which is 90% owned by investment funds managed by Apollo Global Manage ...

, AIM,

Gadu-Gadu Gadu-Gadu ( Polish for "chit-chat"; commonly known as GG or gg) is a Polish instant messaging client using a proprietary protocol. Gadu-Gadu was the most popular IM service in Poland, with over 15 million registered accounts and approximately ...

, ICQ and

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washin ...

networks. Other services available using gateway servers include RSS and

Atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, ...

news feeds, sending

SMS Short Message/Messaging Service, commonly abbreviated as SMS, is a text messaging service component of most telephone, Internet and mobile device systems. It uses standardized communication protocols that let mobile devices exchange short text ...

messages to cellular networks and weather reports. As of 2012, Psi has language packs for 20 languages, with more being created.

Emoticon An emoticon (, , rarely , ), short for "emotion icon", also known simply as an emote, is a pictorial representation of a facial expression using characters—usually punctuation marks, numbers, and letters—to express a person's feelings, ...

packs are supported using the jisp format. Many jisp emoticon packs are available, including ones from AIM,

iChat iChat (previously iChat AV) is a discontinued instant messaging software application developed by Apple Inc. for use on its Mac OS X operating system. It supported instant text messaging over XMPP/Jingle or OSCAR ( AIM) protocol, audio and vid ...

, and Trillian. Psi supports file transfers between other XMPP clients, and it is possible to send to or receive files from other IM networks, if the user's servers support this. Psi supports Contact Is Typing Notification (which works with Yahoo!, MSN, and AIM contacts). Version 0.10, released in January 2006, brought automatically resizing contact list and composing window in chat dialogs, tabbed chats, support for Growl messaging system on

Mac OS X macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and la ...

, window transparency and many other changes. Support of audio and video calls in Psi via

Jingle A jingle is a short song or tune used in advertising and for other commercial uses. Jingles are a form of sound branding. A jingle contains one or more hooks and meaning that explicitly promote the product or service being advertised, usually ...

is implemented via officially supported plugin PsiMedia.

Encryption

Security is also a major consideration, and Psi provides it for both client-to-server (TLS) and client-to-client (

OpenPGP Pretty Good Privacy (PGP) is an encryption program that provides cryptographic privacy and authentication for data communication. PGP is used for signing, encrypting, and decrypting texts, e-mails, files, directories, and whole disk partiti ...

, OTR, and

OMEMO OMEMO is an extension to the Extensible Messaging and Presence Protocol (XMPP) for multi-client end-to-end encryption developed by Andreas Straub. According to Straub, OMEMO uses the Double Ratchet Algorithm "to provide multi-end to multi-end enc ...

OMEMO Plugin
/ref>) via appropriate plugins. Encryption of messages in group chats is supported only via

plugin.

References

External links

Official website

Interview with Justin Karneges
{{DEFAULTSORT:Psi (Instant Messaging Client) 2001 software Free instant messaging clients Free XMPP clients Instant messaging clients for Linux MacOS instant messaging clients Windows instant messaging clients Portable software Software that uses Qt