Signal vs Zulip

Signal uses an advanced end to end encryption protocol that provides privacy for every message every time.

Signal is free and open source software, enabling anyone to verify its security by auditing the code. It's the only private messenger that uses open source, peer-reviewed cryptographic protocols to keep your messages safe.

Signal can be your default SMS/MMS text messenger. Encryption is not possible when sending SMS to your contacts, however.

Signal supports: emoji, pictures, videos, audio, contacts, any location and GIF.

Edward Snowden uses this messenger and recommends it to everyone who is concerned about his privacy.

Signal Desktop is a Chrome extension that allows you to mirror messages from your phone, including replying.

You can easily view all media shared in the chat without scrolling back to when it was shared.

Allows you to "send: messages to yourself and sync to desktop so you can use Signal as a kind of encrypted Pushbullet alternative

Unlike most messenger apps, Signal works reliably in all countries by securely circumventing internet censorship.

The sender credentials can be encrypted with the rest of the message, leaving only the recipient address readable by the Signal server. Even if Signal wanted they couldn't see who is talking with who by this mean.

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.

Zulip is free and open source under the Apache 2.0 license.

Its threaded model helps people working in different timezone's communicate effectively.

With data export tools so you can migrate.

I struggled with Slack, never finding the settings I like to adjust. With Zulip never had such issues.