Why matrix as a chat system?#

There are many services and programs for instant electronic communication. Matrix was chosen because it has the following characteristics:

Open standard (no technical dead end)
Communication protocol for federated real-time communication (no isolated solution but like e-mail with worldwide connectivity)
Differentiated communication possible (1:1, multiple teams, topic-specific)
Decentralized, persistent and interoperable communication (no central control instances, connectable with other protocols and tools)
Data protection: end-to-end encryption standard in 1:1 conversations and (group) rooms, can be switched off in the latter
Web application + desktop client + mobile apps available
The contacts on your own cell phone are not automatically passed on to third parties (no address book upload)
Connection to existing authentication systems
Existing successful security audit
Autonomy and control: locally installable (selfhosted server by envs.net)
Recognize the presence status
Active further development

Detailed explanation of technical terms: https://matrix.org/faq/#definitions