Asterisk is a powerful open-source framework for building communications applications, including VoIP gateways, PBX systems, and conference servers. Developed by Digium (now part of Sangoma), Asterisk enables developers to create robust and scalable telephony solutions for businesses, call centers, and service providers.

Features of Asterisk:

• Asterisk supports multiple communication protocols, including SIP, IAX, and PRI, allowing seamless integration with VoIP and traditional telephony networks.
• With built-in call routing, IVR (Interactive Voice Response), voicemail, and conferencing features, Asterisk provides a flexible and customizable PBX system.
• Asterisk offers powerful APIs such as AMI (Asterisk Manager Interface) and ARI (Asterisk REST Interface), enabling developers to extend and automate telephony functions.
• It includes advanced security features like TLS/SRTP encryption, authentication, and firewall integration to ensure secure communication.

To check Asterisk version:

$ asterisk -V
  

Disclaimer: Asterisk is an open-source software released under the GNU General Public License (GPL). It is not associated with, endorsed by, or sponsored by any specific company. Asterisk is provided "as is," without any warranty, express or implied. Users utilize this software at their own risk. The developers and contributors to Asterisk disclaim any responsibility for any damages, losses, or consequences arising from the use of this software. Users are encouraged to review and adhere to licensing terms and any relevant regulations while utilizing Asterisk.