Kopete is a multi-protocol, free software instant messaging client released as part of the KDE Software Compilation. Although it can run in numerous environments, it was designed for and integrates with the KDE Plasma Workspaces. Developed by kde.org
License: Open Source
ICQ offers a user-friendly experience with a focus on video calls and instant messaging, making it suitable for casual users. On the other hand, Kopete is an open-source application that provides extensive protocol support but may require more technical knowledge to set up, catering to privacy-conscious users and developers.