Web Components are a new browser feature that provides a standard component model for the Web, consisting of several pieces:

• Shadow DOM
  • The current issue tracker.
  • The old issue tracker on W3C bugzilla, which is no longer used.
  • It has been a long-term goal to upstream the Shadow DOM spec into the DOM standard.
• Custom Elements
  • The current issue tracker.
  • The old issue tracker on W3C bugzilla, which is no longer used.
• HTML Imports
  • The current issue tracker.
  • The old issue tracker on W3C bugzilla, which is no longer used.
• HTML Templates
  • HTML Templates were upstreamed into the HTML standard.