Chromebooks are typically built with the intent of performing relatively light work to decrease the amount of hardware required on board (thus reducing overall cost) while pushing the bulk of the power to cloud services, like Google's various browser applications. This allows a new category of users to get online without the need to invest a large amount of money, or for students at school who need a light laptop to swing around campus. As Chromebooks grow in popularity, so does their capabilities and platform.
We have seen some hacky ways of running a full Linux environment on Chromebooks in the past, however, there has not been any official support from Google. Several hints have trickled their way out starting late last year that suggest Linux Virtual Machine support will be added to Chrome OS. It's been reported by Chrome Unboxed that a "Terminal for Chromebooks" is available to some users in the most recent dev build of Chrome OS. The description says:
Develop on your Chromebook. You can run your favorite Linux apps and command-line tools seamlessly and securely. Installing the Terminal will download 200MB of data.
Once downloaded, a new option is added to the Settings menu of Chrome OS. The command line tool gives Chromebooks a whole new capability and value, and will probably be an allure to developers. Chrome Unboxed also explained in a news post that they expect to see the "Project Crostini" with Linux containers as soon as May. This is due to the discovery of a .json file in the Linux commit that has a "supported_on chrome_os:66.", with Chrome OS 66 set for release in late April of this year.