WebKit has been powering Google's Chrome Web browser since its launch in 2008. Google says that "its flexibility, performance, and thoughtful design" made it an obvious choice for Chrome when it launched, but the modern Web and modern Chrome require something different. That something different is Blink.
Google announced that it's developing Blink, a fork of WebKit that will become the rendering engine for Chrome and Chrome OS. Google is moving to its own rendering engine in the hopes that it can reduce the complexity found in both WebKit and Chromium projects.
There is bound to be some concern from Web developers over Google abandoning WebKit. Google anticipated that concern, and said that Blink won't bring a lot of change to how developers currently code for the Web. In fact, the initial work on Blink will be strictly focused on "internal architectural improvements and a simplification of the codebase."
Of course, the greater implication here is that Google is introducing more competition to the Web. Web developers are already having to optimize Web sites for WebKit, Trident and Gecko. Google says that Blink is only a good thing, however, as it feels "multiple rendering engines... will spur innovation and over time improve the health of the entire open Web ecosystem."
The philosophy held by Google seems to be shared by Mozilla as the non-profit announced a new Web rendering engine called Servo yesterday. The engine, being co-developed with Samsung, is being built with the mobile Web in mind.
It will be interesting to see if Google's prediction of increased competition comes true. The company says that it will work with other Web vendors to make sure Web standards are observed, and that interoperability is retained. Still, I've always been of the opinion that we already have too many rendering engines, but Google and Mozilla may just prove my fears unfounded as we move into this next wave of Web development.
If you want to follow Blink development, check out Google's project page.