AT A GLANCE

Slack
Liquid AI
2013
Founded
2023
San Francisco, California
HQ
Cambridge, USA
$1.4 Billion
Total Raised
About $287 million
Stewart Butterfield
Founder
Ramin Hasani, Mathias Lechner, Alexander Amini, Daniela Rus
Collaboration
Type
AI
Acquired by Salesforce ($27.7B)
Status
Private

FUNDING HISTORY

Slack

Series C2014
$43M raised$250M val.
Series D2014
$120M raised$1.1B val.
Series E2015
$160M raised$2.8B val.
Series F2016
$200M raised$3.8B val.
Series G2017
$250M raised$5.1B val.
Series H2018
$427M raised$7.1B val.
Direct Listing (NYSE: WORK)2019
$0 raised$19.5B val.
Acquired by Salesforce2021
$0 raised$27.7B val.

Liquid AI

Seed2023
$38M raised$303M val.
Series A2024
$250M raised$2.4B val.

BUSINESS MODEL

Slack

Slack uses a freemium model. The free tier gives you access to your most recent 90 days of messages and 10 app integrations.

That's enough to get hooked. Then Slack charges per user per month — $8.75/month for Pro, $15/month for Business+, and custom pricing for Enterprise Grid.

The beauty of the model is that one person signs up, invites their team, the team gets addicted, and suddenly the company is paying for 500 seats. It's a virus that charges rent.

Liquid AI

Liquid AI builds foundation models, the big general-purpose brains that power chatbots and other AI tools. The difference is efficiency.

Their models, called Liquid Foundation Models, are designed to do more with far less memory and computing power. Companies pay to use them, either through a cloud API or by running the models on their own machines.

That second option matters. A bank or a hospital often cannot send private data to someone else's server.

Liquid AI lets them keep the model in-house. The pitch to a customer is basically this.

You get strong AI without renting a mountain of expensive chips.

HOW THEY STARTED

Slack

Stewart Butterfield had already done this exact thing once before. In 2002, he was building a massively multiplayer online game called Game Neverending.

The game flopped but one of its features — a photo-sharing tool — became Flickr, which Yahoo bought for $35 million in 2005.

So in 2009, Butterfield did it again. He started a company called Tiny Speck to build another game called Glitch — a quirky, non-violent MMO where players collaborated instead of fighting.

The game was beautiful, weird, and a complete commercial failure. It shut down in November 2012 after never finding a big enough audience.

But the internal communication tool the Glitch team had built for themselves was something special. They had created a searchable, organized messaging system because email was driving them insane.

Every conversation was in channels. Everything was searchable.

Files were shared inline. It was everything email should have been but wasn't.

Butterfield looked at this internal tool and thought: this is the actual product. In August 2013, Slack launched in preview.

Within 24 hours, 8,000 companies had signed up. Within two weeks, it was 15,000.

The growth was so fast that Butterfield said it felt like "trying to drink from a fire hose."

Liquid AI

Liquid AI is a spinout from MIT's Computer Science and Artificial Intelligence Laboratory, better known as CSAIL. The core science came from Ramin Hasani, who spent his PhD studying the nervous system of a tiny worm called C.

elegans. That worm has just 302 neurons and still manages to move, hunt, and react to its world.

Hasani and his collaborators asked a simple question. What if you built an AI that worked more like those neurons and less like a giant static network?

The answer was the liquid neural network, a model whose internal wiring keeps adjusting even after training is done. The team incorporated the company in 2023.

Daniela Rus, who runs CSAIL and is one of the most respected robotics researchers alive, came on as a co-founder. So did Mathias Lechner and Alexander Amini, both longtime research partners of Hasani.

HOW THEY GREW

Slack

Slack grew almost entirely bottom-up. Nobody sold Slack to companies.

Employees adopted it on their own and then convinced their bosses to pay for it. One developer would start using the free version, invite their team, and within weeks the whole department was hooked.

IT departments would discover that half the company was already on Slack before anyone asked for approval.

The integrations strategy was genius. Slack made it dead simple for other software tools to plug into Slack.

Instead of checking Jira for bug reports, Salesforce for deals, and GitHub for code changes, everything pushed notifications into Slack. Slack became the operating system of work — the one app you kept open all day.

Word of mouth was the main growth driver. Slack didn't spend heavily on advertising early on.

They spent on making the product feel delightful. The loading messages were funny.

The emoji reactions were addictive. The search actually worked.

People genuinely liked using it, which is almost unheard of for enterprise software.

Liquid AI

The growth angle is size, or the lack of it. Most frontier models are so heavy they only run in data centers.

Liquid AI aims for models light enough to run on a phone, a car, or a factory robot. That opens doors the giants cannot easily reach.

The AMD partnership pushes the same idea. AMD makes chips, and it wants efficient models that show off its hardware.

So AMD led the Series A and became both an investor and a distribution partner. Liquid AI also releases open models to researchers, which builds a following before the sales team ever makes a call.

THE HARD PART

Slack

Microsoft Teams was the existential threat. When Microsoft bundled Teams for free with Office 365 in 2017, Slack knew it was in trouble.

Microsoft had 300 million Office users who could start using Teams without paying anything extra. Slack even took out a full-page newspaper ad welcoming Microsoft to the chat market — a bravado move that masked genuine fear.

By 2020, Teams had overtaken Slack in daily active users purely on distribution.

The pandemic was a double-edged sword. Remote work exploded demand for Slack, but it also exploded demand for Teams, Zoom, and every other collaboration tool.

Slack's growth accelerated but so did everyone else's. The window where Slack was the obvious default was closing.

Revenue growth started slowing. After years of 50%+ annual growth, Slack's growth rate dropped to the low 30s by 2020.

Wall Street punished the stock, which dropped from its IPO price. The writing was on the wall — Slack couldn't outrun Microsoft alone.

In December 2020, Salesforce announced it was acquiring Slack for $27.7 billion. Butterfield stayed on as CEO until 2023, then left.

Liquid AI

The honest problem is Goliath. OpenAI, Google, Anthropic, and Meta have raised tens of billions of dollars between them.

Liquid AI has raised under $300 million. The transformer architecture those giants use is battle-tested and improving fast.

Liquid AI has to prove its different approach not only works but keeps working as models get bigger. Betting against the most successful design in AI history is bold.

It is also the kind of bet that ends in either a great acquisition or a quiet shutdown, with not much room in between.

THE PRODUCTS

Slack

Slack is the core messaging platform — channels for teams, direct messages, threads for focused discussion, and huddles for quick voice/video calls. Slack Connect lets you message people at other companies directly through Slack instead of email.

Slack Canvas is a built-in document editor for notes and wikis right inside channels. Workflow Builder lets non-technical users automate repetitive tasks without writing code.

The App Directory has 2,600+ integrations — connect Google Drive, Salesforce, Jira, GitHub, or basically any tool your company uses.

Liquid AI

The main products are the Liquid Foundation Models, a family that ships in several sizes so a customer can pick the smallest one that does the job. The second generation, LFM2, arrived in 2025, including LFM2-VL vision-language models built for phones, laptops, wearables and embedded chips.

The company has leaned hard into on-device AI rather than the cloud. The focus is always the same.

Match the quality of a much larger model while using a fraction of the memory and power.

WHO BACKED THEM

Slack

Accel Partners, Andreessen Horowitz, Social Capital, GV (Google Ventures), SoftBank, Dragoneer Investment Group

Liquid AI

It started with a $37.5 million two-stage seed in December 2023 at a $303 million valuation, from OSS Capital, PagsGroup, Automattic (the company behind WordPress), Samsung Next and others. Angels included GitHub co-founder Tom Preston-Werner, Shopify's Tobi Lütke and Red Hat co-founder Bob Young.

Then AMD Ventures led the $250 million Series A in December 2024, which is unusual because AMD is a chipmaker, not a typical venture fund. That backing gave Liquid AI both money and a hardware ally.

When a major chip company writes the lead check on an efficiency-focused model maker, it signals a bet that the future of AI is not just bigger, it is leaner.

MORE COMPARISONS