Linphone - open source SIP client
Téléphone SIP (VOIP)GPL-3.0-only
Sipdroid
Un client SIP (VOIP)GPL-3.0-only
baresip+
VoIP and mobile calling and messaging app based on baresip libraryBSD-3-Clause
baresip
VoIP and mobile calling and messaging app based on baresip libraryBSD-3-Clause
Jami
Share, freely and privatelyGPL-3.0-or-later
Nextcloud Talk
Have private video calls and chat using your own server.GPL-3.0-only