Pidgin is a free and open-source chat client which supports AIM, Google Talk, ICQ, XMPP protocols. Developed by Pidgin
License: Open Source
Miranda IM is a lightweight and highly customizable messaging client, ideal for basic usage, but lacks some advanced features found in Pidgin. Pidgin, on the other hand, offers a broader protocol support, cross-platform functionality, and rich features including voice and video calls, making it suitable for more demanding users.