FreeSWITCH

FreeSWITCH is a software‑defined telecom stack that runs on commodity hardware, from single‑board computers to multi‑core servers, and implements voice, video, and messaging services through direct access to media and signaling layers. Its modular architecture and flexible APIs let developers build custom dialplans, integrate SIP, SMS, and other protocols, and extend functionality with additional modules such as the bundled SignalWire integration.

The platform is self‑hostable, open‑source under MPL‑2.0, and supports Linux, Windows, macOS, and BSD, with installation options ranging from pre‑built packages to Docker‑based source builds. Documentation, issue tracking, and a community Slack channel provide support for developers, while commercial services are available from the sponsoring company for larger deployments.

FreeSWITCH is used by organizations that need deep control over real‑time communications and the ability to scale from modest installations to large‑scale telephony infrastructures without subscription fees or proprietary lock‑in. Its design emphasizes high‑performance media handling and extensibility, making it suitable for voice‑over‑IP, call‑center, and unified‑communication applications.