Google announced it is dropping the open-source Webkit rendering engine that is used in many browsers and is developing its own engine, called Blink.
They have also hinted that the new engine will not only be used in the Chrome web browser, but also in the Chrome OS for smartphones, tablets, e-readers and netbooks. This is a big shift for Google and has advantages and disadvantages going forward.
Firstly the advantages of moving away from Webkit:
Having a custom rendering engine allows you to create highly optimized code, they can create a very fast and flexible engine to work with.
It also allows you to support bleeding edge features before competitors. If, hypothetically, a new version of HTML were being worked on, Google could forge ahead with early support while others would have to wait for Webkit to be updated.
It allows them to create and use custom code for their products. This could give them performance or security advantages over competitors that would use their products. In the Techcrunch article, Google hints at a specific feature that is currently hard to do in Webkit, which is using separate CPUs for iframes. This would be a perfect example of how updating the code for their own engine would be a huge advantage. With all of the worlds CPUs adding cores, from phones all the way up to supercomputers, being able to utilize those extra cores is a major challenge and a huge potential performance gain in certain situations.
It could allow them to add further tools to analyze the behaviour of users in order to more accurately market ads to them.
It also gives them primary control over which parties can contribute to their "open-source" platform.
The disadvantages are numerous as well:
It takes a lot of manpower to manage, code, and validate your own engine. Companies almost unanimously choose Webkit to save money and resources on the engine.
Custom code requires a lot more validation for stability and security testing. You could expose your users to unique security or stability flaws that do not exist on Webkit-based browsers.
If Webkit and Blink diverge in features and code too much from one another, you could have problems with standardization of code. This could lead to issues with certain sites on certain browsers, depending on which rendering engine they used.
Changing the rendering engine can and likely will break some Chrome plug-ins until they are updated.
We will report on the new engine when it is officially adopted by Google with a product launch.
You can find more information on Blink on the Chromium blog.