Alternatives to bIRC for all platforms with any license

Thunderbird

Thunderbird is a free, open source, cross-platform e-mail, news and instant messaging client. The project strategy is modeled after Mozilla Firefox.

Free Open Source Mac Windows Linux BSD PortableApps.com ... Haiku
Extensible by Plugins/Extensions Built-in RSS reader SMTP integration Built-in Calendar ... Calendar integration Categories Customizable Extensible by Plugins/Extensions Free API Gmail integration Google Calendar integration Import from Google Reader HTML Compose Support for IMAP Integrated Chat Integrated Password Manager Integrated Web Browser Legacy addons support Multiple Account support Export to OPML Import feeds from OPML POP3 Support Portable Secure File Sharing Tabbed interface Support for Themes Add a feature

1812 Like
Pidgin

Pidgin is an easy to use, multi-protocol chat client client used by millions. Connect to AIM, MSN, Yahoo, XMPP, and more chat networks all at once. It has built-in...

Free Open Source Mac Windows Linux BSD PortableApps.com ... Xfce
Support for Multiple protocols Support for Multiple protocols Extensible by Plugins/Extensions Supports XMPP ... Multiple languages Multiple Account support Multiple chat protocols Portable Video calling Voice Call Add a feature

1446 Like
HexChat

HexChat is an IRC client based on XChat for Linux , but unlike XChat it’s completely free for both Windows and Unix-like systems. HexChat was...

Free Open Source Windows Linux BSD PortableApps.com Xfce ... MacPorts XQuartz
Portable Add a feature

179 Like
mIRC

mIRC is a popular Internet Relay Chat client used by millions of people, and thousands of organizations, to communicate, share, play and work with each other on IRC...

Commercial Windows
Colored Text Add a feature

85 Like
XChat for Linux

XChat is an IRC chat program for both Linux and Windows. It allows you to join multiple IRC channels (chat rooms) at the same time, talk publicly, private one-on-one...
- Discontinued The program is no longer updated. Last version, 2.8.8, released in May 2010, can be still downloaded from the official website.
Free Open Source Windows Linux
No features added Add a feature

103 Like
irssi

Irssi is a terminal based IRC client for UNIX systems. It also supports SILC and ICB protocols via plugins.

Free Open Source Mac Windows Linux BSD Cygwin
No features added Add a feature

73 Like
Quassel IRC

Quassel IRC is a modern, cross-platform, distributed IRC client based on the Qt4 framework. Distributed means that one (or multiple) client(s) can attach to and detach...

Free Open Source Mac Windows Linux Self-Hosted
QT Based Standalone Add a feature

42 Like
WeeChat

WeeChat is a fast, light and extensible chat client. It runs on many platforms (including Linux, BSD and Mac OS). WeeChat is: - modular: a lightweight core with...

Free Open Source Mac Linux Android BSD Xfce
Command line interface Extensible by Plugins/Extensions Modular System Support for Multiple protocols Add a feature

29 Like
KVIrc

KVIrc is a free portable IRC client based on the excellent Qt GUI toolkit. KVirc is being written by Szymon Stefanek and the KVIrc Development Team with the contribution...

Free Open Source Mac Windows Linux BSD PortableApps.com
Portable Add a feature

37 Like
Kiwi IRC

A hand-crafted IRC client that you can enjoy. Designed to be used easily and freely. More friendly than other webirc clients giving the general public an easy option to...

Free Open Source Web Self-Hosted Chrome
Preconfigurable auto-connect Add a feature

20 Like
ZeroChat

An IRC-like internet chatroom hosted on ZeroNet, a distributed network. 0rc is a fully distributed website, and messages are shared through peers using the ZeroNet...

Free Open Source Mac Windows Linux Web Self-Hosted ... Python JavaScript ZeroNet
Decentralized Distributed Add a feature

8 Like
Smuxi

Smuxi is an irssi-inspired, flexible, user-friendly and cross-platform IRC client for sophisticated users, targeting the GNOME desktop. Smuxi is based on the...

Free Open Source Mac Windows Linux
No features added Add a feature

29 Like
Polari

Polari is an Internet Relay Chat (IRC) client designed for GNOME 3.

Free Open Source Linux GNOME
No features added Add a feature

9 Like
Shout

What is it? Shout is a web IRC client that you host on your own server. What features does it have? * Multiple user support * Stays connected even when you close...
- Discontinued Shout's development has stopped early 2016 and replaced by its official community fork: http://alternativeto.net/software/the-lounge/ . See https://github.com/erming/shout
Free Open Source Web Self-Hosted
No features added Add a feature

12 Like
Textual

Textual is the world's most popular application for interacting with Internet Relay Chat (IRC) chatrooms on OS X. Textual includes two elegantly designed light...

Commercial Mac
No features added Add a feature

17 Like