Google's Chrome browser has been open source from the get-go (through the Chromium project), but not on iOS. Apple demands that browsers use WebKit instead of their own rendering engines, so Google couldn't just use its typical code base and call it a day. However, that all changes today: Google has added the iOS Chrome code into Chromium. Developers who want to build on the iOS app, or just poke around looking for security holes, should now have an easy time seeing what makes it tick.