Hmmm.. listing the KVIrc features ?
Well... why not ?
Here are some key-phrases that came in my mind.

  • User interface
    • Full GUI Based configuration
    • Floatable windows
    • Built-in help browser
    • Themes support (all configurable by GUI or scripting)
    • Pseudo-transparency support (up to the desktop on KDE)
    • Drag & Drop toolbar editing
    • Activity Notifier Pop-Up
    • Status bar with Applet support
    • Unread text mark
    • 14 Languages Translations
  • Network
    • Proxy support (SOCKSv4, SOCKSv5, HTTP)
    • Full IPv6 support (also for DCC transfers)
    • SSL support (also over IPv6)
    • Micryption support
  • Core
    • Modular architecture: unfrequently used features reside in external modules and are loaded only when necessary
    • Extensibility: a huge API for writing extension modules
    • UNICODE support
  • IRC
    • Multi-server connection
    • Notify lists (yes, WATCH is supported)
    • Ignore lists
    • Registered users database
    • Lag meter
    • Configurable logging
    • Standard DCC CHAT and SEND (with resume) support
    • Extended DCC types: VOICE, RSEND, GET, RECV
    • DCC CHAT over SSL
    • DCC bandwidth limit (ability to set it "on the fly")
  • Scripting
    • Built-in scripting language interpreter
      • scalars, arrays and hashes...
      • aliases
      • popups
      • events
      • scriptable toolbars
      • Perl support
      • Ability to translate scripts (by the means of the tr() function)
      • ...
    • Objects support in scripting language: yes, now you can do OOP
    • ...

Hmmm...I hope that's enough to make you curious :D