ictcrm
Open source CRM with built-in contact centre integration
...The CRM side is what you would expect: accounts, contacts, leads, opportunities, cases and campaigns, with the reporting and workflow SuiteCRM already gives you.
What we added is the telephony integration. Calls can be placed from a record, an inbound call can bring the matching record up, and campaign activity flows back into the CRM instead of living in a separate dialer report.
AGPL-3.0 licensed. Suited to teams who want their customer data on their own servers and are willing to run a real CRM rather than a hosted one.