Kiwi IRC - A hand-crafted IRC client that you can enjoy. Designed to be used easily and freely.
MobaXterm - Enhanced terminal for Windows with X11 server, tabbed SSH client, network tools and much more
Colloquy - Traditionally, chat clients on the Mac have been anything but glamorous.
KiTTY - KiTTY is a fork from version 0.70 of PuTTY. It adds extra features to PuTTY.
Terminal on FB Messenger - Take control of your terminal through Facebook Messenger
ConEmu - ConEmu-Maximus5 is a full-featured local terminal for Windows devs, admins and users. Get better console window with tabs, splits, Quake style, copy+paste, DosBox and PuTTY integration, and much more.