General

• light & fast
• available in many languages (en/es/fr/cs/ru/..)
• UTF-8 support
• developed from scratch
• multi-platform: GNU/Linux, *BSD, Mac OS X, Windows, ..
• 100% GPL & free

IRC protocol

• IRC standards compliant
• DCC support: files and chats

Connection

• multi-servers connection, with no limit
• soft, background connection
• IPv6 support
• SSL support
• proxy support
• auto-reconnection

Incoming features

• multi-protocols support by plugins
• GTK+ and Qt GUI
• DCC2 support

Innovating features

• curses, GTK+ and Qt GUI (soon)
• nicklist available on all GUI, including curses
• horizontal and vertical window split
• smart "hotlist" in status bar: partial or full names of channels with activity
• infobar highlight for other channels: any highlight is visible without switching to channel
• keys to jump to last read message and highlights in channel
• incremental text search in buffers
• FIFO pipe for remote control: writing into the FIFO pipe send cmd/text in a running WeeChat
• double charset support: one for decoding, one for encoding messages (global and by server/channel)
• aspell support: check spelling with a language for each channel
• extensible with Perl, Python, Ruby & Lua scripts
• See WeeChat in action!

Other useful features

• status and infobar
• lag indicator
• color for away nicks
• auto completion for nicks, commands and args
• command alias
• auto save chats to files
• everything is customizable
• dynamic setup
• very fast support and bugs correction in a few minutes only!