--
Zulip, open source Slack competitor, is relaunching after being aquired by Dropbox, Zulip 3.0. Current customers include hundreds of startups and large companies from Akamai Tech to Doctors on Demand and even Alcoholics Anonymous. It has the most active open source contributors in the space today compared to any competitor.
Zulip was sold to Dropbox while still in private beta and then Dropbox let Tim Abbot have it back after releasing it as an open source project.
Original startup's founders are Tim Abbott (Kandra Labs / Zulip founder), with Jeff Arnold, Jessica McKellar, and Waseem Daher were his cofounders. Today, they are the founders of Pilot (https://www.indexventures.com/perspectives/pilotcom-raises-40m-in-series-b-funding-and-launches-pilot-tax/).
Zulip's original 2012-2014 startup angel investors (2013) are Drew Houston (founder of Dropbox), Adam d'Angelo (Facebook's first CTO and now founder and CEO of Quora), Diane Greene (cofounder and CEO of VMWare, later CEO of Google Cloud), Paul English (founder of Kayak), Hans Robseron and Sanjit Biswas (cofounders of Meraki), Dharmesh Shah (cofounder of AngelList), Howard Lerman (founder and CEO of Yext), Enrique Salem (CEO of Symantec at the time), and SV Angel.
Zulip was then Acquired by Dropbox in 2014, while in private beta, then given back to founder. At that time Zulip became open source. Most Zulip beta customers tried switching to Slack, and then switched back to Zulip as they found it more productive (despite being a beta that was no longer developed). Dropbox decided not to pursue the team chat market, and Dropbox's legal/engineering leadership then decided to donate the software to the open source community. A dozen engineers flew to Dropbox HQ for a week to help with the engineering work of making it possible to open source Zulip. Dropbox generously donated the Zulip trademark and zulip.com/zulip.org domains.
While there are several open source projects in the team chat space, Zulip has by far more significant contributors than any of the others. Total contributors is a vanity metric; because fixing a typo via the GitHub website counts, it's inflated and doesn't give a useful picture of the breadth of a project's community. The right statistic is how many significant contributors there are - people with dozens or 100 commits ( commits are individual code contributions).
For comparison these are the other major open source team chat projects:
Mattermost: https://github.com/mattermost/mattermost-server/graphs/contributors shows 21 contributors with 100 contributions. This includes fulltime employees for their venture-funded company.
Rocket.Chat: https://github.com/RocketChat/Rocket.Chat/graphs/contributors shows 15 contributors with 100 contributions. This includes fulltime employees for their venture-funded company.
Matrix.org: https://github.com/matrix-org/synapse/graphs/contributors shows 13 contributors with 100 contributions. This includes fulltime employees for their venture-funded company.
###
Most recent headlines
05/01/2027
Worlds first 802.15.4ab-UWB chip verified by Calterah and Rohde & Schwarz to be ...
04/08/2026
Dalet, a leading technology and service provider for media-rich organizations, t...
04/07/2026
April 7 2026, 19:00 (PDT) Detective Conan: Fallen Angel of the Highway Opens in...
01/06/2026
January 6 2026, 05:30 (PST) Dolby Sets the New Standard for Premium Entertainment at CES 2026
Throughout the week, Dolby brings to life the latest innovatio...
30/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
30/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
30/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
30/05/2026
Zero in on one that says yes (and no)
Andy Marken May 29, 2026
0 Comments
Hero image courtesy of Deposit Photos
For content creators the most difficu...
29/05/2026
With InfoComm 2026 just weeks away, NDI is giving attendees plenty of reasons to...
29/05/2026
Reaffirming a partnership that has defined Canadian sports broadcasting since 19...
29/05/2026
Mobile/tablet is No. 2 device for watching TV, suggesting that the sports-production industry needs to take another look at the format
Ring Digital's Sprin...
29/05/2026
Berliner Ensemble, one of Berlin's five major theater companies, has expande...
29/05/2026
Solid State Logic will showcase its new compact, fly-away TCA Tour audio product...
29/05/2026
Gerald (Jerry) Pierce, a pioneering technologist who helped shape the digital transformation of the motion picture industry, passed away last month on April 12 ...
29/05/2026
Paramount+ will be the English-language U.S. home for Barclays Women's Super...
29/05/2026
Further strengthening its virtualisation strategy to fully support broadcasters ...
29/05/2026
Swiss broadcaster Canal Alpha has deployed Harmonic's award-winning, software-based XOS Advanced Media Processor to modernize playout operations across cant...
29/05/2026
PTZOptics will showcase a new generation of intelligent video workflows at InfoComm 2026, June 17-19, Las Vegas. Visitors to booth N8227 will see how PTZOptics ...
29/05/2026
Arizona's Family has launched the Arizona's Family Sports (AZFS) streaming app, a new direct-to-consumer destination for live, local sports. The app is ...
29/05/2026
Starting in 2027, DAZN will be the exclusive home of The Canadian Football Leagu...
29/05/2026
Comcast Business has detailed the advanced network infrastructure it has deploye...
29/05/2026
In two-day event, leaders from academia and industry explored solutions to chall...
29/05/2026
The Basketball Tournament (TBT), now entering their 13th year of competition, ha...
29/05/2026
Roku has launched FOX One as a Premium Subscription on The Roku Channel in the U.S. Roku customers can now subscribe to FOX One using their Roku account for liv...
29/05/2026
In its sixth year, the broadcaster's coverage has become a global brand and ...
29/05/2026
Ratings Roundup is a rundown of recent ratings news and is derived from press re...
29/05/2026
The days are getting longer, the temperatures are rising, and playlists are filling up for the season. With summer around the corner, Spotify's global edito...
29/05/2026
New retro-inspired MPC announced
There are few devices that have gained the status held by Akai Pro's MPC range, and in recent years, the company have s...
29/05/2026
Save up to 30 on acclaimed titles
Following a successful launch at Superbooth 2026, Bjooks have revealed that they will be continuing the Kickstarter campa...
29/05/2026
Binaural monitoring application improved
Genelec have just released an update that brings some powerful new features to their HRTF-based binaural headphone ...
29/05/2026
6 June 2026 at SAE Institute, London, UK
IMSTA FESTA 2026 is almost upon us, with some of the biggest names in pro-audio set to descend upon SAE Institute i...
29/05/2026
Gerald (Jerry) Pierce, a pioneering technologist who helped shape the digital transformation of the motion picture industry, died April 12, 2026, at his home in...
29/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
29/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
29/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
29/05/2026
Comparing 5 AI Video Enhancers for Restoring Old Video Quality
Kate Luvis May 29, 2026
0 Comments
Digitizing VHS, MiniDV, and other legacy formats doe...
29/05/2026
Studio Hamburg Builds New Post Pipeline with DaVinci Resolve Studio
Brie Clayton May 29, 2026
0 Comments
Workflow replaces a patchwork of legacy tools...
29/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
29/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
29/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
29/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
29/05/2026
Share
Copy link
Facebook
X
Linkedin
Bluesky
Email...
29/05/2026
At the Intersection of Music and Dance, an Epic Collaboration Boston Conservatory musicians and dancers found creative parallels in their recent performance o...
29/05/2026
May 29 2026, 09:00 (PDT) Dolby and rednote Bring More Immersive Storytelling to...
29/05/2026
Something fundamental has shifted in how people consume media. Audiences aren't abandoning television or radio content; they're just expanding how, wher...
29/05/2026
Youtube exclusive special drops today
Watch now
UKTV today announces another e...
29/05/2026
Back to All News
The Official Trailer of Physical 100 Italy, on Netflix From Se...
29/05/2026
Genelec announces V2.1 for Aural ID binaural headphone monitoring application posted: 29/05/2026
Aural ID 2.1 enhances binaural monitoring for stereo and ...
29/05/2026
At just 20 years old, Sean Melia from Summerhill Co. Meath has been revealed as the winner of Super Garden 2026. Sean is the youngest ever contestant and winner...
-- 
