ZNC is an IRC bouncer with many advanced features such as a built-in web interface, persistent connection (detaching), multiple users, per channel playback buffer, SSL, IPv6, transparent DCC bouncing, and c++ module support, to name a few.
- Highly powerful and flexible module system with dozens of modules available
- Very active community in #znc on EFnet (also on freenode but less active)
- Handles multiple users in one running process
- Multiple irc clients can connect to a given user
- Plays back channel text when your client connects
- Built-in webadmin interface for configuring using a browser
- Fully IPv6 and ssl compatible between.. client <-> ZNC <-> irc
- Bounce DCC chats and transfers through ZNC to stay anonymous
- iPhone PUSH support for mobile colloquy and prowl (via modules)
- *twitter module for watching searches/mentions/etc and sending tweets
- You can /detach #annoying_chan to have ZNC to stay in the channel but hide it from your clients
- Can load modules to authenticate off of IMAP or SASL, or write one to use your own custom system
- Has a *partyline module for talking in channels with other users on your same ZNC instance
- Has modules to change your nick when you're detached, keep trying for your primary nick, rejoining channels on kick, etc. etc.
There are no 4 star reviews.