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 more feature-rich and customizable instant messaging client that supports a wide range of protocols and offers extensive plugin support, making it ideal for power users. In contrast, Instantbird is a lightweight and user-friendly application that caters to casual users but lacks many of the advanced features found in Pidgin.