Support of Linux and Windows will happen. Mac support is planned too.

• Consoles
  • Command and message history on consoles
  • Formatting
    • Depending on message type (notice, error, etc.)
    • mIRC formatting
    • ANSI colours - Planned
    • CTCP formatting - Planned
  • Logging - Planned
    • Text - Planned
    • HTML - Planned
  • Message grouping, if a user messages a number of times without interruption the nick is posted only once.
  • Supports URLs - Replaces them with hyper links, soon this will be added by plug-in too.
• CTCP
  • DCC
    • CHAT
    • DCC FILE (File transfers) - Planned
    • Passive DCC - Planned
    • DCC Server - Planned
• GUI Channel list
  • Search web
  • Supports ELIST, list Extensions.
• Message Statistics - Will be supported by plug-in
• Server
  • Can connect to multiple servers
  • Perform buffer, a list of commands sent to the server once connected.
  • Supports NAMESX
  • Supports UHNAMES
  • Supports UTF-8
  • IPv6¹⁾
  • SSL
• Plug-in Support
  • Ability to extend and create GUI - Still growing
  • Add command handlers to give the user new commands to type.
  • Add message handlers to work with incoming server messages
• Tree to make it easier to navigate
  • Items highlight with differently depending on a message, event or highlight trigger.
  • Tree can be hidden from the interface or permanently in settings.
• Unlimited nicknames, the list of nicks to try at connect is not limited to two.

There could be more I can't remember and there are more on the way. You should also take a look at the screen shots.