Modern

-sleek interface takes full advantage of your 32-bit operating system
-consumes very little memory and system resources
-automatically remembers your favorite servers, channels, and people
-includes advanced features such as 'minimizing to the tray', 'timestamp toggle', and instantly 'clickable URL hyperlinks'.

Flexible

-supports connection to many servers at once, without launching a separate copy of the program
-userlist manager utilizes advanced algorithms to intelligently op, ban, ignore, or notify you of friends, foes, and acquaintances
-colors, fonts and other preferences are completely customizable with clean, uncluttered dialogs
-the source code is provided for many of the built-in commands (in TCL)

Fast

-unparalleled text display speed without any of the 'tricks' (such as lazy write) employed by other Windows clients
-multithreaded DCC architecture implements Turbo DCC (TDCC), providing the highest possible file transfer throughput
-the speed of large channel listings are governed by the speed of your connection, not by the quality of the client code
-even 500K of loaded TCL scripts cannot noticeably slow it down

Extensible

-scripting is based on an industry-standard language from Sun Microsystems (there are many books available on TCL)
-create your own commands, event handlers, popup menus, and hotkeys with absolutely no limitations on script size or the number of loaded scripts
-the output and behaviour of every command and response can be modified or subverted to suit your desires
-advanced users can extend the language endlessly with a standard Win32 DLL interface

Standards-Based, supporting...

-every IRC command
-common CTCP (Client-To-Client Protocol) commands
-IRC 'attributes' (bold, underline, reverse)
-'de facto standards' such as mIRC color and Turbo DCC