Pidgin is a free and open-source chat client which supports AIM, Google Talk, ICQ, XMPP protocols. Developed by Pidgin
License: Open Source
Pidgin is a versatile multi-protocol chat client known for its user-friendly interface and plugin support, making it suitable for a wide range of users. KVIrc, on the other hand, is a lightweight and highly customizable IRC client that excels in scripting and offers built-in DCC file transfer, catering more to advanced users.