You are looking at the HTML representation of the YAML format.
HTML is good for debugging, but probably is not suitable for your application.
Please see "format" parameter documentation at the API help for more information.
---
query: 
  namespaces: 
    - 
      id: -2
      *: Media
    - 
      id: -1
      *: Special
    - 
      id: 0
      *: 
    - 
      id: 1
      *: Talk
    - 
      id: 2
      *: User
    - 
      id: 3
      *: User talk
    - 
      id: 4
      *: Fringe
    - 
      id: 5
      *: Fringe talk
    - 
      id: 6
      *: Image
    - 
      id: 7
      *: Image talk
    - 
      id: 8
      *: MediaWiki
    - 
      id: 9
      *: MediaWiki talk
    - 
      id: 10
      *: Template
    - 
      id: 11
      *: Template talk
    - 
      id: 12
      *: Help
    - 
      id: 13
      *: Help talk
    - 
      id: 14
      *: Category
    - 
      id: 15
      *: Category talk