Examine source code of EarthSpace

{
  "theme": {
    "images": {
      "theme_frame": "top2.jpg"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#707070"
    }
  },
  "version": "2.0",
  "name": "EarthSpace",
  "manifest_version": 2,
  "description": "Created for 1280x1024 resolution. Use with <a href=\"https://addons.mozilla.org/sk/firefox/addon/10550/developers\" rel=\"nofollow\">https://addons.mozilla.org/sk/firefox/addon/10550/developers</a> and image <a href=\"https://outgoing.prod.mozaws.net/v1/beb6d6517a151bf7ab01f8b8d11035cf12e78165582a9cc08edc85ff6590e15b/http%3A//i475.photobucket.com/albums/rr119/peter-andreus/stred.jpg\" rel=\"nofollow\">http://i475.photobucket.com/albums/rr119/peter-andreus/stred.jpg</a>"
}