--
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
24/12/2025
What is AI good for? Posted by MTI Film on December 24, 2025
What is AI good for?
What is AI good for?
It's been three years since ChatGPT first cap...
24/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
24/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
24/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
24/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
24/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
24/12/2025
Back to All News
Love, Fights, and Everything in Between: Badly in Love' Returns for Season 2
Entertainment
24 December 2025
GlobalJapan
Link copied t...
24/12/2025
Scripps Research study links sleep variability with sleep apnea and hypertension How consumers' digital activity trackers could enable personalized health s...
23/12/2025
How guilas Cibae as Dominican Winter League Games Are Locally Produced for Glob...
23/12/2025
BitFire's Jim Akimchuk on Supplying Scalability and Customization in the Clo...
23/12/2025
CAMB.AI Enables European Athletics to Offer Multi-Language SupportPlan is to eventually offer translation into all languages spoken in EuropeBy Ken Kerschbaumer...
23/12/2025
Analysis: As sports media values trend negative, scarcity and quality are king By Callum McCarthy, Editor-at-Large
Monday, December 22, 2025 - 14:08
Print ...
23/12/2025
ESPN, Disney, and NBA Return to the Animated Altcast Fray With Second Edition of...
23/12/2025
End the Year on a High Note and Donate to the Sports Broadcasting Fund Today! By Ken Kerschbaumer, Editorial Director
Tuesday, December 23, 2025 - 12:25 pm
...
23/12/2025
The year is winding down, the weather outside is frightful, and it's the perfect time to escape into a story that warms the heart. For listeners looking for...
23/12/2025
A Zeus motor is hot fire tested at L3Harris' Camden, Arkansas, solid rocket ...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Lightware will exhibit several major product innovations at ISE 2026, including the new USB-C BOOSTER-V1, Google Meet. integration for various Taurus UCX models...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Taking the Stage at Carnegie Hall-On a Global Scale Boston Conservatory Orchestra students reflect on their epic concert marking the 80th session of the UN Gene...
23/12/2025
Back to All News
Netflix's The Great Flood and Culinary Class Wars 2 Top Gl...
23/12/2025
Back to All News
Stranger Things By the Numbers: How the Global Phenomenon Shap...
23/12/2025
Experience the power of WO Automation for Radio's newest service, the System Effectiveness Review. Designed to help you achieve more, a System Effectiveness...
23/12/2025
23 Dec 2025
VEON's Beeline Kazakhstan and Rakuten Symphony Collaborate to A...
23/12/2025
Back to All News
How Steamy Can It Get? Single's Inferno' Season 5 Pre...
23/12/2025
Back to All News
33 Million Global Viewers on Netflix Watched Jake Paul vs. Ant...
23/12/2025
New technique lights up where drugs go in the body, cell by cell Scripps Research scientists developed a technique that maps drug binding in individual cells th...
22/12/2025
SVG New Sponsor Spotlight: Presidio's Neerav Shah on the Role of Its Captiva...
22/12/2025
Hitting the bullseye: Sky Sports readies itself for the biggest PDC World Darts ...
22/12/2025
Unique skillset: Bringing new directors to the world of darts at The Worlds with...
22/12/2025
Gravity Media prepares for a flight of fancy with the PDC World Darts Championsh...
22/12/2025
One hundred and eighty: Gravity Media on hitting the production bullseye at the ...
22/12/2025
The Famous Group's Jon Slusser on Fascinating Fans Through Immersive Content...
22/12/2025
ESPN's Meg Aronowitz on Continuing High-Quality Broadcasts of Collegiate Spo...
22/12/2025
ESPN Takes Data-Driven Storytelling to New Heights with MNF Playbook with Next ...
22/12/2025
For a decade, popular German podcast Fest & Flauschig has hosted an annual Chris...
22/12/2025
Paramount Scores Largest Share Increase Among Distributors as Paramount and CBS...
22/12/2025
New multi-year deal integrates Roku's data to fuel Nielsen's measurement suite
Roku gains access to Nielsen's streaming ratings, showing The Roku C...
22/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
22/12/2025
Berklee Wrapped 2025: Our Top News and Stories A look back at a year highlighted by faculty milestones, major film and television projects, Bob Dylan's ho...
22/12/2025
The works of Plato state that when humans have an experience, some level of change occurs in their brain, which is powered by memory - specifically long-term me...
22/12/2025
Partnership integrates complementary satellite data and AI analytics to enhance security, infrastructure, and environmental monitoring solutions for global cust...
22/12/2025
Workflows allow you to create a sequence of planned events which may be added to your template(s) or inserted directly into your sequential or background playli...
-- 
