IRC vs Flock

The IRC protocol is public and open, it is mature and stable, and has been implemented in numerous projects. This means that it can be used freely, for both open-source and commercial projects.

IRC offers choice. Choice in clients (mobile, desktop, web), in scripts those clients run, in servers and features those servers have. You can even set up your own server.

Compared to other common solutions, IRC can be ignored when you are occupied doing something else. Most clients don't pester you with sounds or distracting visuals.

Every notable IRC client supports mentions - notifying you when your name is mentioned in the chat. The mentions in IRC are comparably better than Discord. Mentions used in Discord are easily abused; this doesn't happen in IRC. If someone's talking about you, you get a notification in IRC. This doesn't happen in something like Discord.

IRC has been around since 1988, so there is a ton of existing software to work with it. Everything from clients, to chat bots, to bouncers is already built.

You can choose your favorite server for an IRC network.

No need to sign up for access, confirm your e-mail address. Just choose a nickname and you're done.

IRC is user friendly if you use something like hexchat or kiwi webchat.

Direct Client-to-Client allows users to share files in a similar way to torrenting.

Twitter hashtags came from IRC channel names.

They have apps for Windows, Mac, Chrome, iOS, Android and web interface. And all the chat sessions are always on sync.

It is half the price of Slack and full of nice features like polls, assign to do's, etc.

Unlike its rivals, it not only allows you to receive events, but also allows you to push content to it and receive various user action events.

Moving a team or organization to flock does not require any setup from the company's IT team. At max, what might be required would be to whitelist their domain in case the organization's IT team has gotten external domains blocked. You can simply download Flock and invite others in your organization by using their email ids in order to start collaborating. That's all there is in the name of setup.

Most of its features are free, even video conferences. But also they have a Pro version with unlimited chat history, Active Directory integration among other things.

There is no limit on the number of groups or of group members. Similarly, within a team you can have unlimited members. There is no limit of number of teams too.

Flock is offering an app that is faster than Slack.

For every team, the permissions and restrictions can easily be set over the participating members and the conversations they are having.

Posting messages is more fun with them in addition to emojis.

There are multiple options like slash commands, message buttons, chat buttons, attachment picker etc., where the integrations can surface inside the native app. This greatly eases the discoverability of a integration, making it really easy for the team members to find and use the integrations.