~320M daily users. Combines chat, meetings and files in a single bound volume. The standard reference for most offices.
Subjects: all in one · enterprise · bundled
002 SL
REF 002.SL / Chat First
Slack
filed under Messaging
~47M daily users. Known for the deepest integration index. Widely circulated among startups. From ~$7.25 per user.
Subjects: integrations · chat · startups
003 ZM
REF 003.ZM / Meetings
Zoom
filed under Video
~300M daily meeting joins. The leading reference for video calls and webinars. Chat held in a thinner appendix.
Subjects: video · webinars · meetings
004 GM
REF 004.GM / Google Native
Google Meet
filed under Workspace
Browser based, no install. Cross referenced with Gmail, Calendar and Docs. Free to borrow.
Subjects: browser · google · simple
005 WX
REF 005.WX / Secure
Webex
filed under Cisco
Catalogued for security and compliance. Preferred in regulated enterprise and government collections.
Subjects: security · compliance · enterprise
006 DC
REF 006.DC / Community
Discord
filed under Communities
200M+ monthly. Strong in voice channels and community reading rooms. Informal, not for compliance heavy use.
Subjects: voice · community · free
Librarian's note — No single volume answers every question. Keep Teams on your main shelf if you use Microsoft 365, then check out Slack, Zoom or the others as your reading requires.
All product and company names are trademarks of their respective owners and are used for identification only. Figures are approximate analyst and public estimates for 2026 and are subject to change. Independent comparison, not affiliated with, sponsored by, or endorsed by any company named. For general informational purposes only. Results may vary.