Could Aside Become the Second Cursor? An AI Browser Built on Chromium

TL;DR: Browsers’ insides have converged on one engine, Chromium, and browser automation has spent 20 years moving in one direction: outside code drives the browser inside. Aside is a browser made by copying and modifying Chromium, and it reversed that direction. An agent lives inside the browser, and the browser opens itself to the outside through a CLI and MCP. It has the same structure as Cursor, which grew from a modified copy of VS Code, but in 2026, the year Aside launched, OpenAI’s browser shut down less than a year after release. This article charts that lineage with screenshots from the app itself and lays out the criteria for answering “Could it become the second Cursor?”

Contents

1. What is Aside?
2. In the Beginning Was the Chromium Engine
3. The Automation Stages: From Selenium to Playwright
4. Aside Reversed That Direction
5. Could Aside Become the Second Cursor?
6. Summary

1. What is Aside?

Aside is a macOS browser that introduces itself as “the most intelligent AI assistant, but it’s a browser.” Inside sites you’re already logged into, an agent reads the screen and clicks on your behalf. I covered the concept in the What is Aside? explainer, so this article looks at the company and its lineage.

The company information is on the Y Combinator official page.

Item	Details	Source
Company	San Francisco. The homepage copyright notice reads Aside Computer Inc.; the browser build’s copyright notice reads At Your Side Inc.	Y Combinator, aside.com footer, version screen below
Founded	2024; Y Combinator Fall 2025 batch	Same page
Founders	Jun Kim (CEO), Chanhee Lee (CPO), Sanghun Lee (CTO); all three are from South Korea	YC page, eomag interview
Team	5 people	YC page
Launch	June 23, 2026; the launch post drew 1.6 million views	eomag interview
Foundation	Copied and modified Chromium (internal name Bromium), Chromium 152	Interview, measured screen below

In the interview, cofounder Chanhee Lee says he got into YC on his seventh application. After the batch ended with no results, he spent two months in a state of not wanting to write a single line of code. In January 2026 the CEO proposed an AI browser, and the product launched five months later is today’s Aside.

2. In the Beginning Was the Chromium Engine

To understand Aside, you first need to know what “building a new browser” means in 2026. The answer is simple: nobody builds a browser from scratch anymore. They take Chromium, which Google has released publicly, and use it.

Chromium is a browser’s insides. In car terms, it’s the engine and frame. Companies attach different exteriors (colors, button placement, names), but the part that reads web pages and draws them on screen is the same. That’s why Chrome, Edge, Naver Whale (Naver’s browser), and Samsung Internet look different in name yet show the same pages almost identically.

Exterior (browser name)	Engine underneath	Worldwide share, August 2026
Chrome, Edge, Samsung Internet, Opera, Naver Whale (Naver’s browser), Brave, Vivaldi, Arc	Chromium	About 79% (sum of only the four largest listed here)
Safari	Apple WebKit	About 16%
Firefox	Mozilla Gecko	About 3%

The share figures come from StatCounter, August 2026. Roughly eight out of ten people use browsers whose engine is Chromium.

Browsers aren’t the only case. Many desktop apps also have Chromium underneath:

• VS Code (the app programmers write code in)
• Slack, Discord (messaging apps)
• GitHub Desktop

These apps are built with a method called Electron, which embeds Chromium inside the app so you can build desktop apps the way you’d build web pages. Since anyone who can make a website can make a desktop app, many companies took this route.

So in 2026, “building a new browser” means “copying Chromium and modifying it.” Aside was built that way too, and you can see the evidence right inside Aside.

3. The Automation Stages: From Selenium to Playwright

For over 20 years, making code move a browser on a person’s behalf has developed in one direction: outside code drives the browser inside.

20 years of browser automation: outside code drives the browser inside

2004 Selenium Started as an in-house tool at one company; a method that injects commands into the browser

→

2009, 2018 WebDriver Merged into Selenium; became an international standard in 2018

→

2017 Puppeteer Built by Google's Chrome team; drives Chrome through the official channel Chrome opened

→

2020 Playwright Built by the former Puppeteer team at Microsoft, covering three browsers with one approach

Here are the years and sources.

Tool	Started	Built by	What it changed	Source
Selenium	2004	ThoughtWorks, Jason Huggins	Turned browser testing into code	Wikipedia
WebDriver	Joined 2009, standard 2018	Simon Stewart; the international standards body W3C	Replaced different control methods per browser with one standard	Same document
Puppeteer	2017	Google’s Chrome team	Drove Chrome running without a screen through the official channel	InfoQ 2017
Playwright	January 2020	Microsoft, former Puppeteer team	Chrome, Firefox, and Safari-family browsers in one approach	Wikipedia

The direction held in the AI agent era too:

• Claude Code and Cursor attach servers such as Playwright MCP to drive the browser from outside.
• The browser remains a tool, and the outside agent makes the decisions.
• For someone seeing this scene for the first time, the article is What is Playwright?.

4. Aside Reversed That Direction

One day while using Aside, I came across this summary on Threads:

It’s simply a Chromium fork that makes the browser, which people used to hook up to AI CLIs, IDEs, and the like via MCP, connectable in reverse from the browser itself.

(Threads, anonymous user)

It’s a single line, but it’s accurate. Checking it against the official docs:

A table of the three channels shows the difference in direction.

Channel	What it does	How it differs from Playwright
CLI (aside "…")	Hands a task to the agent inside the browser with one sentence from the terminal	Delegation, not control. The agent inside the browser makes the decisions
MCP (aside mcp)	Outside agents such as Claude Code and Codex connect to Aside as an MCP server	The browser is the server, and the coding agent is the client
REPL (aside repl, an interactive runner where you type commands one line at a time and see results right away)	Directly manipulates tabs, screenshots, and screen elements with code similar to Playwright’s	Same direction as the past 20 years, but inside a browser that holds your logins and memory

Reversed direction: who calls whom

1. Selenium, Playwright Outside code → inside browser The browser is an empty tool. Logins, memory, and decisions all belong to the outside
2. Aside Inside browser → outside agent The browser holds the logins, the memory, and an agent, and opens itself to the outside through CLI and MCP

The company also disclosed what it costs to maintain this copy. In the July 2026 update, when it moved from Chromium 149 to 150, a cofounder said a five-person team follows new upstream Chromium versions faster than Perplexity, Dia, or Atlas (PiunikaWeb, July 7, 2026). The Chromium 152 in the measured screen above is the result of two more upgrades after that. Chromium often patches security holes, and if the copier can’t keep up, only that browser is left with the holes. Forking and modifying gains a lot, but it’s also a debt you have to pay every month.

5. Could Aside Become the Second Cursor?

The same Threads post continued:

Whether Aside can grow the way Cursor did by forking VS Code is an open question. Cursor already did browser launching and automation before, and MCP worked too; and the Atlas browser that GPT pushed earlier has been discontinued.

(Threads, anonymous user. The original post writes the name as a Korean transliteration, “Astra”; from context it refers to OpenAI’s Atlas, so I corrected it in the quote.)

Aside’s side also uses the comparison to Cursor. In the interview, Chanhee Lee says that no one thought developers would pay for an editor until Cursor changed that, and that browsers are the same. Here the two companies are side by side.

Item	Cursor	Aside
What was copied and modified	VS Code (public code editor)	Chromium (public browser engine)
What the copy gained	Access inside the editor; features impossible with extensions	Access inside the browser; an agent with login sessions and memory
What already worked before	AI autocomplete via extensions	Browser control via Playwright MCP
Company	Anysphere, founded 2022	Aside Computer Inc., founded 2024
Scale	$29.3 billion valuation (November 2025), $3 billion annual revenue (May 2026)	Team of 5; 20,000 users two weeks after launch
Source	Wikipedia	YC page, eesel summary

The structure is the same. You copy a public skeleton, gain inside access that extensions can’t provide, and make things you could already do much easier. The difference is how dense the competition is. Cursor was first to fork an editor, but by 2026 many companies had already jumped into AI browsers, and one of them had already shut down.

AI browser	Maker	Status as of September 2026	Source
ChatGPT Atlas	OpenAI	Launched October 2025; shutdown announced July 9, 2026; service ended August 9. Features moved to the ChatGPT desktop app and Codex	TechCrunch, 9to5Mac
Comet	Perplexity	Started July 2025 as a $200-a-month, subscription-only product; made free worldwide in October 2025, later expanded to mobile	CNBC
Aside	Aside Computer	Launched June 2026, Chromium 152	Measured in this article

TechCrunch’s article on the Atlas shutdown read it as OpenAI concluding that the browser is a feature, not a destination. Aside is the opposite: the browser is the product. It keeps up with Chromium updates monthly, puts the password manager and memory inside the browser, and opens that browser to outside agents. It’s a setup where a small company pushes its copy into the space a big company left.

6. Summary

Sources for this article

• Y Combinator company page, Aside official help, developer page, Aside for Developers, Aside changelog
• eomag, Chanhee Lee interview, PiunikaWeb, Chromium update
• StatCounter browser market share, Wikipedia Chromium, Wikipedia Electron
• Wikipedia Selenium, InfoQ Puppeteer, Wikipedia Playwright, Wikipedia Cursor
• TechCrunch, Atlas shutdown, 9to5Mac, Atlas shutdown

The Aside-related facts in this article (company information, Chromium version, CLI and MCP setup) were checked on September 15, 2026, against the official page and inside the Aside app. The claim of first place in benchmarks is the company’s own announcement. Browser share figures and company statuses are as of that date and may change.