The talk is about Matrix RTC (Real-Time Communication) and its potential applications beyond instant messaging. Matrix is described as an open, federated, secure, and decentralized real-time communication network that can be used for various purposes such as chat, voice over IP, VR applications, and IoT data. The speaker explains the basics of Matrix RTC, including its peer-to-peer semantics, the ownership of business logic by the clients, and the use of back-end components like MCUs or SFUs. They also discuss the implementation of Matrix RTC in the Element Call client and its integration with Element Web using widgets. The talk concludes with a demo of the Element Call client and a preview of a project called Third Room, which is a social collaboration platform built on top of Matrix RTC using VR technology. The speaker mentions future plans for Matrix RTC, including implementing whiteboard functionality, end-to-end encryption, and the cascaded selective forwarding units.