Early last year, there was an internal proposal by the Chromium team to implement a sidebar interface for Chrome, providing extension developers with another way to deliver extra functionality and content. If you were planning to deploy something using this API, it's time to make new plans as it's just been axed.
Image by niu tech
Chrome developer Mike Tsao delivered the news yesterday on the API's issue thread on Chromium's Google Project site, the primary justification being keeping the browser as simple as possible:
We will not be proceeding with this feature request. We recognize that there is a significant number of you who will be disappointed with this decision, evidenced in part by the many stars on this issue. We debated it extensively, both inside the team and with members of the community. In the end we decided that the WontFix resolution was more in keeping with Chrome's core value of simplicity.
If you're wondering, yes, there are extensions out there that use the API. It's unclear whether the Chromium team will dump the code, breaking such extensions, or just depreciate it, though given Google's on-going stance on reducing Chrome's complexity, the former is more likely.