freepbx - FreePBX is a web-based open source GUI that controls and manages Asterisk (PBX).
HubSpot - Grow Better With HubSpot: Software that's powerful, not overpowering. Seamlessly connect your data, teams, and customers on one CRM platform that grows with your business.
Asterisk - An open source telephony switching and private branch exchange service for Linux.
ActiveCampaign - Integrated email marketing, marketing automation, and small business CRM. Send beautiful newsletters, setup behavioral based automations, and benefit from sales automation.
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.
Pardot - Salesforce B2B marketing automation