When comparing Wire vs Zulip, the Slant community recommends Wire for most people. In the question“What are the best Skype alternatives?” Wire is ranked 4th while Zulip is ranked 24th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Libre/open source
Pro End-to-end encryption
Pro Clean, modern interface
Pro Privacy-respecting
Pro Intuitive user interface
Wire's user interface is quite intuitive to use, still it has everything required for a complete experience. Settings are very clean and allows you to turn on/off some features which might be disturbing for some, like link previews and emoji conversion.
Pro Swiss legislation
Registered in Switzerland.
Pro Helps keep track of different conversations
Instead of rooms or channels Zulip is built around topics. This allows you to have multiple conversations at the same time without conversations interfering with each another. It also allows you to reference conversations without clutter.
Pro Free and open source software
Zulip is free and open source under the Apache 2.0 license.
Pro Easy asynchronous conversations
Its threaded model helps people working in different timezone's communicate effectively.
Pro Apps for every platform
Pro Hosted or on-premise
With data export tools so you can migrate.
Pro Intuitive interface
I struggled with Slack, never finding the settings I like to adjust. With Zulip never had such issues.
Cons
Con Centralized
Con No End-to-End Encryption
Not even for private one-to-one messages, let along group chats.
Con Takes some getting used to
As most chat software uses the concept of channels or rooms, getting in the habit of splitting each topic off in a separate category can require some getting used to and discipline.