Video: Slack vs Stride

Slack brings all your communication together in one place. It's real-time messaging, archiving and search for modern teams. Create open channels for the projects, groups and topics that the whole team shares. Slack searches whole conversations, not just individual messages, so you can find what you’re looking for no matter who said what or when they said it. Slack free open-source (self-hosted) alternatives are: Mattermost, Rocket.Chat, Zulip
Stride is a new way for teams to talk, meet, decide and do. Make talking about doing. Turn your next great conversation into action by creating and assigning tasks in your rooms. Having a fruitful discussion? Save an outcome by marking a chat as a decision, and reference them later anytime.
Face to face in the news:

2018 - Stride opens its API to keep up with Slack

Stride, the Atlassian’s Slack competitor is opening API to all developers. Thanks to this, Stride developers will get access to a new app management console that makes it easier for them to manage their app’s credentials, for example. In addition, Atlassian is also making a new documentation interface available for Stride developers. Developers can create new Bots and other experiences that center around sending and receiving messages. Apps, however, can also display their own user interface for showing contextual information in the Stride sidebar with the help of a JavaScript API. Atlassian says about 1,000 developer signed up for early access to the API. Thereby Stride gets more developer-friendly if compared vs Slack

2017 - Slack gets cool screen-sharing tool to strike back at Stride

The collaborative workplace platform Slack is adding one of its most requested features: screen-sharing tool. Slack previously allowed users on a call to share screens with other collaborators, but now, Slack users can also allow others to interact with the screen in a number of ways, including typing, drawing, and editing on the screen. Enabling this new interactive screen-sharing ability on Slack looks pretty simple. During a Slack call, you just need to hit the "Share control of your screen" button which will then give each participant on the call their own cursor. They can now type, edit, and draw on the shared screen. Thereby Slack now provides more real-time collaboration options if compared vs Stride

2017 - Atlassian launched Stride - its new Slack competitor

Atlassian, that has long offered a team communications service HipChat, now launched more Slack-like service called Stride. It includes both a smart text-based messaging service and a fully featured video and audio conferencing service that enables frictionless meetings without the need to install any plug-ins. Stride's free version supports an unlimited amount of users, group audio and video, as well as support for bots and third-party integrations. The main limit here is that the free version only stores the last 25,000 messages and you only get 5GB of file storage. For $3 per user/month, those limits completely disappear and you also get support for guest access, screen sharing and advanced user management.