Slack vs Riot.im : Which is Better?

Slack

Slack is a cloud-based team collaboration tool. Developed by Slack Technologies, Inc.

License: Freemium

Apps available for Mac OS X Windows Linux Online Android

Riot allows teams to communicate across a wide range of collaboration apps.

License: Open Source

Apps available for Online Android iPhone iPad Self-Hosted

Feature	Slack	Riot.im
Collaborative
Extensible by Plugins/Extensions
Group chat
Group collaboration
IFTTT integration
Onboarding
Out Of The Box
Reactions
App integration
Channel manager
Channels
Direct file uploading
Electron based
HIPAA compliant
Integrated File Sharing
Live Push Notifications
Support for @mentions
Multi Channel
Multiple channels
Multiple teams
Real time collaboration
Team Collaboration
Team work
Video calling
Video chat
Voice Call
Ad-free
Chat Bot
On-premises software
Self-hosted in intranet or private cloud
Threaded Conversations
Chat organizer
End-to-End Encryption
Decentralized
Security & Privacy
Live Chat
Federation
Chat
Security focused
Encrypted chat
Share your screen
Gmail integration
Video Conferencing
Privacy-friendly
Content Templates
File sharing
Gantt-charts
Apps that Sync with Google Calendar
Built-in File transfer
GitHub integration
Slack integration
Active Directory integration
Add-ons
Clean design
Community based
Custom widgets
Direct Messaging
DRM Free
Federated
LDAP support
MarkDown support
Matrix.org protocol
Message redaction
Mobile friendly
Moderation tools
Per-room avatars
Privacy focused
Read receipts
File Sending
Server Moderation
Server side history
Social network
Text chat
Typing notifications
User Management
User mentions
Video/Audio Calling
Voice chat
Web-Based
Web Integaration
Stickers
Lightweight
Cloud sync
Peer-To-Peer
Support for Multiple protocols
Custom Backgrounds
Forums