SlackBuildsOrg/network/toxcore

Tox is a free (as in liberty and price) peer to peer, distributed, multimedia
messenger. Tox can provide a superior instant messaging experience than current
market offerings by using existing technologies such as dispersed networking
and strong cryptography. Files can be shared as fast as you and your partner's
Internet connection allows, audio calls are instantaneous, and there are no
arbitrary limits to how many people you can have in a group conversation.

Additional libconfig dependency is needed for tox-bootstrapd daemon,
together with:

  DAEMON=yes ./toxcore.SlackBuild