In 2016, a bunch of tech companies went public, including Coupa, Line, Nutanix, Talend, and Twilio. Now a new batch is in the running for an initial public offering (IPO).

Many of these companies get their money by selling to other companies, typically the largest companies in the world. But there are also a few IPO contenders that are already household names because they have millions and millions of end users. Should even one or two of these go public in 2017, this will be remembered as a big year for tech IPOs. One of the contenders, in particular, could raise $4 billion in its deal — an ungodly sum in recent years, though not without precedent.

All the companies on this list have recently been highlighted as IPO contenders by private company research startup CB Insights, IPO exchange traded funds (ETF) manager Renaissance Capital, or both firms.

Without further ado, here’s our top 2017 tech IPO candidates:

Airbnb

The startup that lets you pay to stay in other people’s homes and rent out your own is eight years old now, and it has taken on about $4 billion in funding. Think it’s about time for that thing to go? I’ll say. Airbnb’s investors include Google Capital Capital G, Sequoia Capital, General Atlantic, and Tiger Global.

Anaplan

Cloud-based financial planning software provider Anaplan reportedly hit unicorn status earlier this year. Investors include Coatue Management, DFJ Growth, Salesforce, and Workday.

AppNexus

This ad tech company counts publishers like Bloomberg, Dow Jones, and ESPN as its customers. Investors include News Corp.

Apttus

Last year, Salesforce acquired one of Apttus’ top competitors, SteelBrick, a deal that was notable because Salesforce had previously invested in Apttus. Other investors in the quote-to-cash software company include Gulf Islamic Investments and Iconiq Capital. In September, chief executive Kirk Krappe told Fortune that the company was looking to go public in the first half of 2017.

BuzzFeed

LOL. Yeah. That BuzzFeed. All those goofy articles over the years have helped BuzzFeed accumulate a major audience and finance more serious journalism. In November, NBCUniversal confirmed to Variety that it had invested another $200 million in BuzzFeed. Other investors include Lerer Hippeau Ventures, RRE Ventures, and Hearst Ventures.

Cloudflare

The content distribution network (CDN) and distributed denial of service (DDoS) mitigation service is often in the news because so many companies rely on it to keep their websites going even under heavy loads of traffic. Cloudflare last announced funding in 2015, and, at the time, cofounder and chief executive Matthew Prince said an IPO could happen as soon as 2017.

Credit Karma

About a year and a half ago, personal finance company Credit Karma said it had raised $175 million at a $3.5 billion valuation. Recently, the company introduced a tax preparation service, challenging the likes of H&R Block and Intuit.

Domo

Cloud-based business analytics service Domo said in March that it had held its valuation at $2 billion for its most recent $131 million round. It’s competing against some of the biggest technology companies, including Microsoft and Salesforce.

Dropbox

It’s been nearly two years since cloud syncing and sharing service Dropbox saw competitor Box go public. This year, Dropbox reached 500 million users. It last disclosed a funding round in 2014 at a valuation of $10 billion.

ForeScout

Network security company ForeScout, which was founded in 2000, announced a $76 million funding round at a billion-dollar valuation in January 2016. In September, Reuters reported that it had started interviewing banks that could be its IPO underwriters.

Glassdoor

Perhaps best known for storing employees’ reviews of their workplaces, Glassdoor makes money through advertising job openings and enhancing companies’ profile pages. Investors include T. Rowe Price.

Gusto

The payroll and benefits startup has been taking on customers from competitor Zenefits after the latter was found to be practicing without licenses in some states. A year ago, Gusto confirmed it had raised an “opportunistic insider round.” Investors include Capital G, GV, Kleiner Perkins Caufield & Byers, and Y Combinator.

Illumio

The cybersecurity company counts Morgan Stanley, Plantronics, and Salesforce among its customers. Investors include Andreessen Horowitz, Formation 8, and General Catalyst Partners.

InsideSales

Based in Utah, predictive sales company InsideSales last announced funding in 2015, with Microsoft and Salesforce Ventures participating.

Instacart

The grocery delivery company last raised funding in 2015. That year it also hired its first chief financial officer and made some layoffs. In 2016, Instacart announced several partnerships, including Cash & Carry, PlateJoy, and Publix.

Medallia

A 15-year-old company specializing in customer experience management, Medallia last announced funding in 2015, with top-flight firm Sequoia Capital participating.

MuleSoft

Cloud app integration software company MuleSoft has been in a position to go public for years, but has chosen to hold off. “There are a lot of advantages to continuing to stay private, including flexibility in how we run the business,” MuleSoft founder Ross Mason told VentureBeat in an email in 2015, when the company last announced funding.

Okta

This identity management software company became a unicorn when its valuation passed the $1 billion mark in 2015, and it now has more than 800 employees. It’s setting up a second headquarters in San Jose, 50 miles south of its current headquarters in San Francisco.

Palantir

Some of Palantir’s most prominent backers have reportedly disagreed about whether the big data company should go public. But a few months ago, chief executive Alex Karp said the company was looking at an IPO. Numerous government agencies are Palantir customers.

Pinterest

The company best known for letting users pin save photos and other content to boards now has more than 150 million monthly active users, but it last raised money in 2015.

Qualtrics

Cloud software for surveying employees can apparently be a lucrative business, given the rise of Qualtrics. The Utah company last raised money in 2015; investors include Insight Venture Partners and Sequoia Capital.

Razer

A company that has become known for its mechanical keyboards, mice, and other hardware, Razer announced in 2016 that it would begin investing in startups. Also, it acquired a little company called THX.

Slack

The trendy team communication app’s valuation of $3.8 billion is crazy high, even though the product has only been around for less than three years. But it has lots of competitors, including Microsoft, which launched Teams in November, while still keeping Yammer around. Slack investors include Accel Partners, Comcast Ventures, GGV, Index Ventures, Social Capital, Spark Growth, and Thrive Capital.

Snap

Snap Inc. was Snapchat until a short time ago, when the startup announced its first foray into hardware with the launch of Spectacles glasses (with included camera). Now Snap Inc. is positioning itself as a camera company, not just another messaging app (albeit one that remains popular with younger generations and has seen multiple features copied by Facebook). And it’s on a hiring spree. The inevitable IPO will be huge whenever it happens.

Spotify

The music streaming service has faced formidable competition from Apple, and it confirmed a billion-dollar debt round in March. Spotify brought in $187.1 million in revenue in 2015, up from $159 million in the prior year, according to a filing. “As an investor … we’re looking forward to an IPO at some point in time,” Northzone general partner Par-Jorgen Parson told Reuters recently.

Sprinklr

In July, the New York-based social media management company announced that it had raised $105 million in new funding at a $1.8 billion valuation. It employs more than 1,200 people, and its customer list includes McDonald’s, Microsoft, Nike, and P&G.

Stripe

Popular online payment provider Stripe raised $150 million in November at a reported $9.2 billion valuation. “We are very happy as a private company right now,” Will Gaybrick, the startup’s chief financial officer, told Business Insider last week.

Tanium

Endpoint security company Tanium last raised money in 2015. In 2016, VMware announced TrustPoint, a product that packages up Tanium’s software.

Thumbtack

A company that specializes in helping people find the right professionals for specific jobs, Thumbtack last announced funding in 2015, at a valuation of $1.3 billion, according to the New York Times. Shortly thereafter, it hired its first chief financial officer. Investors include Tiger Global and Sequoia Capital.

Uber

The app-enabled cab service has raised at least $12.46 billion in funding, according to CB Insights data, and its valuation of $68 billion, per the Wall Street Journal, is higher than that of any other unicorn. Its balance sheet exceeds $11 billion, and among its investors is the Public Investment Fund of Saudi Arabia.

Unity Technologies

Provider of a popular gaming engine, Unity announced a $181 million funding round in July. Investors include DFJ Growth, Sequoia Capital, and Thrive Capital. Unity says 770 million people play games made with its engine.