Typing about:labs in Canary or developer builds of Chrome shows list of experimental features to enable and try them. Google renames about:labs to about:flags in Chromium build to warn users that these are experimental features that can change,break or disappear at any time.

Chrome flags

Actually about:labs is GUI for command line flags for chrome development team to test out various new features instead of need to enable each feature through command line flag.

Chrome labs

Ben Goodger Chrome user interface leader says to his team that “ there should be no judgment call you make about whether or not you add your experimental toggle to about:labs the answer is always YES ADD IT to about:labs”.

He also says “As a side note we are going to rename about:labs to make it sound less friendly.

Currently Chromium build shows experimental features about:labs as about:flags.