There are only two-and-a-half reasons to build a browser, and they couldn't be more different in intent and outcome, even when they look superficially similar. Learning to tell the difference is helpful for browser project managers and engineers, but also working web developers who struggle to develop theories of change for affecting browser teams.

Like Platform Adjacency Theory and The Core Web Platform Loop, this post started^[1] as a set of framing devices that I've been sketching on whiteboards for the best part of a decade. These lenses aren't perfect, but they provide starting points for thinking about the complex dynamics of browsers, OSes, "native" platforms, and the standards-based Web platform.

The reasons to build browsers are most easily distinguished by the OSes they support and the size and composition of their teams ("platform" vs. "product"). Even so, there are subtleties that throw casual observers for a loop. In industrial-scale engineering projects like browsers headcount is destiny, but it isn't the whole story.

Web As Platform #

This is simultaneously the simplest and most vexing reason to build a browser.

Under this logic, browsers are strategically important to a broader business, and investments in platforms are investments in their future competitiveness compared with other platforms, not just other browsers. But none of those investments come good until the project has massive scale.

This strategy is exemplified by 1990s-era Andreesen's goal to render Windows "a poorly debugged set of device drivers".

The idea is that the web is where the action is, and that the browser winning more user Jobs To Be Done follows from increasing the web platform's capability. This developer-enabling flywheel aims to liberate computing from any single OS, supporting a services model.

A Web As Platform play depends on credibly keeping up with expansions in underlying OS features. The goal is to deliver safe portable, interoperable, and effective versions of important capabilities at a fast enough clip to maintain faith in the web as a viable ongoing investment.

In some sense it's a confidence-management exercise. A Web As Platform endgame requires the platform increasaes expressive capacity year over year. It must do as many new things each year as new devices can, even if the introduction of those features is delayed for the web by several years; the price of standards.

Platform-play browsers aim to grow and empower the web ecosystem, rather than contain it or treat it as a dying legacy. Examples of this strategic orientation include Netscape, Mozilla (before it lost the plot), Chrome, and Chromium-based Edge (on a good day).

Distinguishing Traits #

• Ship on many OSes and not just those owned by the sponsor
• Large platform teams (>200 people and/or >40% of the browser team)
• Visible, consistent investments in API leadership and capability expansion
• Balanced benchmark focus
• Large standards engagement footprint

The OS Agenda #

There are two primary tactical modes of this strategic posture, both serving the same goal: to make an operating system look good by enabling a corpus of web content to run well on it while maintaining a competitive distance between the preferred (i.e., native, OS-specific) platform and the hopefully weaker web platform.

The two sub-variants differ in ambition owing to the market positions of their OS sponsors.

Browsers as Bridges #

OSes deploy browsers as a bridge for users into their environment when they're underdogs or fear disruption.

Of course, it would be better from the OS vendor's perspective if everyone simply wrote all of the software for their proprietary platform, maximising OS feature differentiation. But smart vendors also know that's not possible when an OS isn't dominant.

OS challengers, therefore, strike a bargain. For the price of developing a browser, they gain the web's corpus of essential apps and services, serving to "de-risk" the purchase of a niche device by offering broad compatibility with existing software through the web. If they do a good job, a conflicted short-term investment can yield enough browser share to enable a future turn towards moat tactics (see below). Examples include Internet Explorer 3-6 as well as Safari on Mac OS X and the first iPhone.

Conversely, incumbents fearing disruption may lower their API drawbridges and allow the web's power to expand far enough that the incumbent can gain share, even if it's not for their favoured platform; the classic example here being Internet Explorer in the late 90s. Once Microsoft knew it had Netscape well and truly beat, it simply disbanded the IE team, leaving the slowly rusting husk of IE to decay. And it would have worked, too, if it weren't for those pesky Googlers pushing IE6 beyond what was "possible"!

Browsers as Moats #

Without meaningful regulation, powerful incumbents can use anti-competitive tactics to suppress the web's potential to disrupt the OS and tilt the field towards the incumbent's proprietary software ecosystem.

This strategy works by maintaining high browser share while never allowing the browser team to deliver features that are sufficient to disrupt OS-specific alternatives.

In practice, moats are arbitrage on the unwillingness of web developers to understand or play the game, e.g. by loudly demanding timely features or recommending better browsers to users. Incumbents know that web developers are easily led and are happy to invent excuses for them. It's cheap to add a few features here an there to show you're "really trying", despite underfunding browser teams so much they can never do more than a glorified PR for the OS. This was the strategy behind IE 7-11 and EdgeHTML. Even relatively low share browsers can serve as effective moats if they can't be supplanted by competitive forces.

Apple has perfected the moat, preventing competitors from even potentially offering disruptive features. This adds powerfully to the usual moat-digger's weaponisation of consensus processes. Engineering stop-energy in standards and quasi-standards bodies is nice and all, but it is so much more work than simply denying anyone the ability to ship the features that you won't.

Tipping Points #

Bridge and moat tactics appear very different, but the common thread is control with an intent to suppress web platform expansion. In both cases, the OS will task the browser team to heavily prioritise integrations with the latest OS and hardware features at the expense of more broadly useful capabilities — e.g. shipping "notch" CSS and "force touch" events while neglecting Push.

Browser teams tasked to build bridges can grow quickly and have remit that looks similar to a browser with a platform agenda. Still, the overwhelming focus starts (and stays) on existing content, seldom providing time or space to deliver powerful new features to the Web. A few brave folks bucked this trend, using the fog of war to smuggle out powerful web platform improvements under a more limited bridge remit; particularly the IE 4-6 crew.

Teams tasked with defending (rather than digging) a moat will simply be starved by their OS overlords. Examples include IE 7+ and Safari from 2010 onward. It's the simplest way to keep web developers from getting uppity without leaving fingerprints. The "soft bigotry of low expectations", to quote a catastrophic American president.

Distinguishing Traits #

• Shipped only to the sponsor's OSes
• Browser versions tied to OS versions
• Small platform teams (<100 people and/or <30% of the browser team)
• Skeleton standards footprint
• Extreme focus on benchmarks of existing content
• Consistent developer gaslighting regarding new capabilities
• Anti-competitive tactics against competitors to maintain market share
• Inconsistent feature leadership, largely focused on highlighting new OS and hardware features
• Lagging quality

Searchbox Pirates #

This is the "half-reason"; it's not so much a strategic posture as it is environment-surfing.

Over the years, many browsers that provide little more than searchboxes atop someone else's engine have come and gone. They lack staying power because their teams lack the skills, attitudes, and management priorities necessary to avoid being quickly supplanted by a fast-following competitor pursuing one of the other agendas.

These browsers also tend to be short-lived because they do not build platform engineering capacity. Without agency in most of their codebase, they either get washed away in unmanaged security debt, swamped by rebasing challenges (i.e., a failure to "work upstream"). They also lack the ability to staunch bleeding when their underlying engine fails to implement table-stakes features, which leads to lost market share.

Historical examples have included UC Browser, and more recently, the current crop of "secure enterprise browsers" (Chromium + keyloggers). Perhaps more controversially, I'd include Brave and Arc in this list, but their engineering chops make me think they could cross the chasm and choose to someday become platform-led browsers. They certainly have leaders who understand the difference.

Distinguishing Traits #

• Shipped to many OSes
• Tiny platform teams (<20 people or <10% of the browser team)
• Little benchmark interest or focus
• No platform feature leadership
• No standards footprint
• Platform feature availability lags the underlying engine (e.g., UI and permissions not hooked up)
• Platform potentially languishes multiple releases behind "upstream"

Implications #

This model isn't perfect, but it has helped me tremendously in reliably predicting the next moves of various browser players, particularly regarding standards posture and platform feature pace.^[2]

The implications are only sometimes actionable, but they can help us navigate. Should we hold out hope that a vendor in a late-stage browser-as-moat crouch will suddenly turn things around? Well, that depends on the priorities of the OS, not the browser team.

Similarly, a Web As Platform strategy will maximise a browser's reach and its developers' potential, albeit at the occasional expense of end-user features.

The most important takeaway for developers may be what this model implies about browser choice. Products with an OS-first agenda are always playing second fiddle to a larger goal that does not put web developers first, second, or even third. Coming to grips with this reality lets us more accurately recommend browsers to users that align with our collective interests in a vibrant, growing Web.

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1. I hadn't planned to write this now, but an unruly footnote in an upcoming post, along with Frances' constant advice to break things up, made me realise that I already had 90% of it of ready. ↩︎

2. Modern-day Mozilla presents a puzzle within this model.

   In theory, Mozilla's aims and interests align with growing the web as a platform; expanding its power to enable a larger market for browsers, and through it, a larger market for Firefox.

   In practice, that's not what's happening. Despite investing almost everything it makes back into browser development, Mozilla has also begun to slow-walk platform improvements. It walked away from PWAs and has continued to spread FUD about device APIs and other features that would indicate an appetite for an expansive vision of the platform.

   In a sense, it's playing the OS Agenda, but without an OS to profit from or a proprietary platform to benefit with delay and deflection. This is vexing, but perhaps expected within an organisation that has entered a revenue-crunch crouch. Another way to square the circle is to note that the the Mozilla Manifesto doesn't actually speak about the web at all. If the web is just another fungible application running atop the internet (which the manifesto does center), then it's fine for the web to be frozen in time, or even shrink.

   Still, Mozilla leadership should be thinking hard about the point of maintaining an engine. Is it to hold the coats of proprietary-favouring OS vendors? Or to make the web a true competitor? ↩︎