Asterisk - An open source telephony switching and private branch exchange service for Linux.
Raindrop.io - All your articles, photos, video & content from web & apps in one place.
FreeSWITCH - FreeSWITCH is an open-source media application designed to support popular protools such as SIP and WebRTC and provides a platform to develop voice and video applications.
Linker - Cloud based bookmark manager
FusionPBX - FusionPBX is an open source FreeSWITCH GUI.
Bookmark OS - Bookmark OS is like Mac or Windows optimized for bookmarks.