You are looking at the HTML representation of the RAW format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the RAW format, set format=raw.
See the complete documentation, or API help for more information.
{
    "query": {
        "namespaces": {
            "-2": {
                "id": -2,
                "case": "first-letter",
                "*": "Media",
                "canonical": "Media"
            },
            "-1": {
                "id": -1,
                "case": "first-letter",
                "*": "Special",
                "canonical": "Special"
            },
            "0": {
                "id": 0,
                "case": "first-letter",
                "*": "",
                "content": ""
            },
            "1": {
                "id": 1,
                "case": "first-letter",
                "*": "Talk",
                "subpages": "",
                "canonical": "Talk"
            },
            "2": {
                "id": 2,
                "case": "first-letter",
                "*": "User",
                "subpages": "",
                "canonical": "User"
            },
            "3": {
                "id": 3,
                "case": "first-letter",
                "*": "User talk",
                "subpages": "",
                "canonical": "User talk"
            },
            "4": {
                "id": 4,
                "case": "first-letter",
                "*": "MediaWiki",
                "subpages": "",
                "canonical": "Project"
            },
            "5": {
                "id": 5,
                "case": "first-letter",
                "*": "MediaWiki talk",
                "subpages": "",
                "canonical": "Project talk"
            },
            "6": {
                "id": 6,
                "case": "first-letter",
                "*": "File",
                "canonical": "File"
            },
            "7": {
                "id": 7,
                "case": "first-letter",
                "*": "File talk",
                "subpages": "",
                "canonical": "File talk"
            },
            "8": {
                "id": 8,
                "case": "first-letter",
                "*": "MediaWiki",
                "subpages": "",
                "canonical": "MediaWiki"
            },
            "9": {
                "id": 9,
                "case": "first-letter",
                "*": "MediaWiki talk",
                "subpages": "",
                "canonical": "MediaWiki talk"
            },
            "10": {
                "id": 10,
                "case": "first-letter",
                "*": "Template",
                "canonical": "Template"
            },
            "11": {
                "id": 11,
                "case": "first-letter",
                "*": "Template talk",
                "subpages": "",
                "canonical": "Template talk"
            },
            "12": {
                "id": 12,
                "case": "first-letter",
                "*": "Help",
                "subpages": "",
                "canonical": "Help"
            },
            "13": {
                "id": 13,
                "case": "first-letter",
                "*": "Help talk",
                "subpages": "",
                "canonical": "Help talk"
            },
            "14": {
                "id": 14,
                "case": "first-letter",
                "*": "Category",
                "canonical": "Category"
            },
            "15": {
                "id": 15,
                "case": "first-letter",
                "*": "Category talk",
                "subpages": "",
                "canonical": "Category talk"
            },
            "100": {
                "id": 100,
                "case": "first-letter",
                "*": "Portal",
                "canonical": "Portal"
            },
            "101": {
                "id": 101,
                "case": "first-letter",
                "*": "Portal talk",
                "canonical": "Portal talk"
            },
            "102": {
                "id": 102,
                "case": "first-letter",
                "*": "Property",
                "canonical": "Property"
            },
            "103": {
                "id": 103,
                "case": "first-letter",
                "*": "Property talk",
                "subpages": "",
                "canonical": "Property talk"
            },
            "104": {
                "id": 104,
                "case": "first-letter",
                "*": "Type",
                "canonical": "Type"
            },
            "105": {
                "id": 105,
                "case": "first-letter",
                "*": "Type talk",
                "subpages": "",
                "canonical": "Type talk"
            },
            "106": {
                "id": 106,
                "case": "first-letter",
                "*": "Form",
                "canonical": "Form"
            },
            "107": {
                "id": 107,
                "case": "first-letter",
                "*": "Form talk",
                "subpages": "",
                "canonical": "Form talk"
            },
            "108": {
                "id": 108,
                "case": "first-letter",
                "*": "Book",
                "canonical": "Book"
            },
            "109": {
                "id": 109,
                "case": "first-letter",
                "*": "Book talk",
                "canonical": "Book talk"
            },
            "170": {
                "id": 170,
                "case": "first-letter",
                "*": "Filter",
                "canonical": "Filter"
            },
            "171": {
                "id": 171,
                "case": "first-letter",
                "*": "Filter talk",
                "subpages": "",
                "canonical": "Filter talk"
            },
            "420": {
                "id": 420,
                "case": "first-letter",
                "*": "Layer",
                "canonical": "Layer"
            },
            "421": {
                "id": 421,
                "case": "first-letter",
                "*": "Layer talk",
                "canonical": "Layer talk"
            },
            "446": {
                "id": 446,
                "case": "first-letter",
                "*": "Education Program",
                "canonical": "Education Program"
            },
            "447": {
                "id": 447,
                "case": "first-letter",
                "*": "Education Program talk",
                "canonical": "Education Program talk"
            },
            "490": {
                "id": 490,
                "case": "first-letter",
                "*": "Profile",
                "canonical": "Profile"
            },
            "491": {
                "id": 491,
                "case": "first-letter",
                "*": "Profile talk",
                "canonical": "Profile talk"
            },
            "710": {
                "id": 710,
                "case": "first-letter",
                "*": "TimedText",
                "canonical": "TimedText"
            },
            "711": {
                "id": 711,
                "case": "first-letter",
                "*": "TimedText talk",
                "canonical": "TimedText talk"
            },
            "828": {
                "id": 828,
                "case": "first-letter",
                "*": "Module",
                "subpages": "",
                "canonical": "Module"
            },
            "829": {
                "id": 829,
                "case": "first-letter",
                "*": "Module talk",
                "subpages": "",
                "canonical": "Module talk"
            },
            "_element": "ns"
        }
    }
}