There are so many game engines, why are there so few browser engines?
Is it harder to make a browser engine than a game engine? Yes. It's much harder to make a browser engine. Why? Simply because browsers need to be compatible with literally millions of existing sites. While game engines only need to be compatible with it's own current major release. If we could drop all the baggage of current web technologies and build a new browser engine supporting new APIs, then it would be easy (comparatively speaking). Yes. You have TLS, HTTP, HTML and javascript as an starter. Then you have CSS and video decoding and if you want/need an plugin from a foreign developer for EME(encrypted audio and video). Everyone of them also have different versions and/or features that you need to implement. Game engines on the other hand have an base you can build upon (DirectX, Metal, Vulkan, OpenGL) and that abstract things away. Browsers can build upon the same base as game engines. The issue isn't so much the technologies available (though I've often cited reasons I'm unhappy with the status quo of web technologies) but more than game engines don't need to be compatible with every game in existence. Whereas web browsers need compatibility with every website. It's compatibility that's hard. Another example of how compatibility is hard is looking at how operating systems support older applications. A lot of the problems Windows has is due to its commitment to backwards compatibility. Whereas Apple take a different approach and expect developers to port their applications to newer releases of macOS. Because browser engines need to be all able to run the exact same applications (web pages) in exactly the same way. They are pretty straightforward to judge on that single metric. Game engines run only their own games, each has its own specializations and choices, and they have and need zero compatibility with each other. It's hard to finance a browser engine. And you can't just write a quick one. It takes lots of resources. There's also the difficulty of getting your development money back given the dominance of the two big ones, chrome, and Firefox. It took google, with all of its resources, years to write chrome to give an example of how hard it is to write one. Writing a game engine is much easier in getting resources and payback. JavaScript had many limitations in the past and it has been very hard to make something fast enough and using the underlying hardware... Until now. A lot of work is getting done in this, and in the future we'll probably use something like WASM and underlying hardware directly from browser-based JavaScript. It is a exciting future. In 1999-2001 we used IE and VBSCRIPT and ActiveX. It meant other OSes and web browsers could not use our site. But management wanted a Microsoft solution. I guess it is - the API surface (HTML and JavaScript) is enormous and it needs to run websites that are not designed specificly for that browser engine, the opposite of game engines, where the game is designed for the engine. Thanks for all the answers.