For many years, we've seen lots of blog posts and conversation on the topic of "browser engine diversity". I'd like to offer a slightly tilted view of this based instead on "the health of the ecosystem", and explain why I think this is more valuable measure and way to discuss these topics.
Back in January, Jeremy Keith compared the complexity of browser engine diversity to political systems...
If you have hundreds of different political parties, that’s not ideal. But if you only have one political party, that’s very bad indeed!
I like this analogy because I think he's right in even more ways than he intended. It's almost self-evident: 1 is too few, a hundred is too many - it's just chaos and noise. But what is the ideal number? This answer dogs us a lot, in part because it is not only unanswerable, it's actually kind of a red herring. I think there's something to this that leads to an important takeaway about how we think about the problem...
The interesting part about this analogy is that the simple number of political parties isn't actually a very meaningful measure: Parties can differ a lot, or they can differ a little. 6 parties that barely disagree is quite a different thing than 3 that disagree substantially. Further, it's not simply a matter of giving voice to every dissenting opinion that matters either: There are political parties formed on ideas of hate, for example. Adding those doesn't add good things. In short, what really matters is the goal of those numbers.
In the case of the political analogy, the real aim is about what makes for a healthy, effective and just model of governance. Similarly on the topic of "browser engine diversity", I believe that the real goal is "What makes for a healthy and effective ecosystem?" and that the numbers we frequently talk about (and how) can easily lead us into perhaps the wrong takeaways.
It is fairly common that discussions of browser diversity point to the Web's own history for examples of "why engine diversity matters": IE vs Netscape are often held up. IE's dominance and ability to dictate the market (or even kill it in this case) was overcome by diversity. This is true, but very incomplete: There's a lot more beneath the surface...
Consider, for example, the fact that for a time there were only two mainstream browsers - and the very dominant one (IE) was both entirely proprietary and based on a single proprietary OS.
Consider how different this could have been, if IE had been open source and properly licensed. Even if Microsoft didn't want it to run on other operating systems, someone else could step in and fill that gap. If Microsoft walked away from the Web, or worse, went belly up, someone could fork and take over the project. If, for any reason at all, the primary maintainer cannot prioritize - other people and organization could more directly invest in advancements.
A while later, Opera's Presto was very interesting, even multi-OS - but ultimately similarly proprietary.
So, while we had greater 'diversity', these numbers alone aren't a great measure of the overall health of the ecosystem.
This is in stark contrast to the situation today: In important ways, we are a more diverse, efficient and healthier ecosystem with the three multi-os, open source engines we have left (Blink, Gecko and WebKit) than when we had had more and were dominated by projects that weren't that at all.
Today, the 3 that remain are all multi-OS.
"...Wait, even WebKit?" - you, just now.
Yes! I'm glad you asked! The GNOME flagship Epiphany/Web browser for Linux is WebKit based -- and billions of devices are based on Embedded WebKit. PS4 is a fun example of something lots of people might be familliar with -- not only the Web browser on your PS4, but in fact lots of the UI itself is made with Web content running in a WebKit based browser. But chances are pretty good that you encounter emdedded WebKit all the time: On cable boxes, smart TVs and appliances, kiosks, car and airplane infotainment systems, digital signage and so on.
This is possible because WebKit (and all of the engines today) are open source. Because of this, they all receive investments more widely than the org that maintains them, and that's expanding in important ways that are very good for the health of the ecosystem.
This also leads to lots of interesting new opportunities. For example, we are the creators/maintainers of WPE, the official WebKit Port for Embedded that powers tons of those devices mentioned above. This matters a lot because a rising tide lifts all boats in the commons. You can see an example of this in that Igalia is advancing work on SVG2 and hardware acceleration for SVG in WebKit - a topic which has failed to get the prioritization for years, but is especially critical for lots of embedded use cases. If you're interested in this, as well as some interesting history of SVG, WebKit, HTML/CSS and embedded browsers, have a listen to this.
There is another interesting thing here that is always left out of these discussions but I think is considerably interesting in this reframing. A funny little quirk of history is that while we say there are 3 rendering engines, that's only partially true.
More specifically, there are 3 modern browser rendering engines, and a bunch of other rendering engines that aren't that.
Amazon, for example, has a renderer that is used for ebooks and printing. PrinceXML has a renderer used for print. Antenna house too. And there are more still.
For the most part, these are proprietary and what they do and don't support isn't necessarily clear cut. Their support for modern standards is pretty ragged and the gaps are only likely to grow faster. This is a shame as there are lots of potentially useful things for these industries, like Houdini which are unlikely to ever exist for them.
This is a topic I'd love to see discussed more for several reasons - but mainy they center on the fact that it is just harder for us to move forward together if things are too fragmented. Instead of growing together and a rising tide lifting all boats - the boats are kind of all in entirely different bodies of water.
I would love to see some effort to resolve this. Imagine if these vendors came into the fray and either invested in basing their work on modern engines (hopefully various), or pulled together to create something new. That might be the one practical way we could arrive at an actual viable 4th engine somehow.
Most of these engines also contain some things that were developed in standards organizations but which no browser supports... That's kind of why they were created. However, there are new opportunities to align...
Web engine architectures are like a lot of engineering projects - they grow, they get crufty, you get locked into certain boundaries that you know you'd like to escape. However,until you do you can't really afford to tackle certain kinds of problems. That's a big part of why browser engines today don't do a lot of the things you needed to fill their use cases. Browser architectures have traditionally, generally not been well-prepared for the problems of print or ebooks, and that's part of why we find ourselves in the current situation.
However, for many years, there has been much rework and rearchitecture of layout engines aimed at solving precisely the fundamental sorts of things that prevented those sorts of things from being considered.
Stir in that most of our office suites and things are now web based and there's considerable incentives to figuring out things like good print and pagination.
But it's not just the projects being open source that matters, it's also that this affords us new opportunities for standardization itself.
Ultimately, it is the calculus of prioritization which impacts our ability to get things done almost more than anything else. Historically, lots of companies get together and, effectively, ask that a very few companies do the work. They are big organizations with big investments, to be sure - but they are all constrained by hard limits. The gauntlet of issues surrounding our ability to prioritize everything from attention to actual implementation have stymied many a topic.
But in this new age, companies like Igalia are showing that there is potentially a whole new game here: Where centralized, concrete investments from outside that small group can lift up the commons, benefit everyone and help drive progress.
In other words: Things are better and healthier because we continue to find better ways to work together. And when we do, everyone does better.