You are looking at the HTML representation of the JSON 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 JSON format, set format=json.
See the complete documentation, or API help for more information.
{
    "query": {
        "namespaces": {
            "-2": {
                "id": -2,
                "case": "first-letter",
                "*": "M\u00e9dia",
                "canonical": "Media"
            },
            "-1": {
                "id": -1,
                "case": "first-letter",
                "*": "Speci\u00e1ln\u00ed",
                "canonical": "Special"
            },
            "0": {
                "id": 0,
                "case": "first-letter",
                "*": "",
                "content": ""
            },
            "1": {
                "id": 1,
                "case": "first-letter",
                "*": "Diskuse",
                "subpages": "",
                "canonical": "Talk"
            },
            "2": {
                "id": 2,
                "case": "first-letter",
                "*": "U\u017eivatel",
                "subpages": "",
                "canonical": "User"
            },
            "3": {
                "id": 3,
                "case": "first-letter",
                "*": "Diskuse s u\u017eivatelem",
                "subpages": "",
                "canonical": "User talk"
            },
            "4": {
                "id": 4,
                "case": "first-letter",
                "*": "Bomosil",
                "subpages": "",
                "canonical": "Project"
            },
            "5": {
                "id": 5,
                "case": "first-letter",
                "*": "Diskuse k Bomosil",
                "subpages": "",
                "canonical": "Project talk"
            },
            "6": {
                "id": 6,
                "case": "first-letter",
                "*": "Soubor",
                "canonical": "File"
            },
            "7": {
                "id": 7,
                "case": "first-letter",
                "*": "Diskuse k souboru",
                "subpages": "",
                "canonical": "File talk"
            },
            "8": {
                "id": 8,
                "case": "first-letter",
                "*": "MediaWiki",
                "subpages": "",
                "canonical": "MediaWiki"
            },
            "9": {
                "id": 9,
                "case": "first-letter",
                "*": "Diskuse k MediaWiki",
                "subpages": "",
                "canonical": "MediaWiki talk"
            },
            "10": {
                "id": 10,
                "case": "first-letter",
                "*": "\u0160ablona",
                "canonical": "Template"
            },
            "11": {
                "id": 11,
                "case": "first-letter",
                "*": "Diskuse k \u0161ablon\u011b",
                "subpages": "",
                "canonical": "Template talk"
            },
            "12": {
                "id": 12,
                "case": "first-letter",
                "*": "N\u00e1pov\u011bda",
                "subpages": "",
                "canonical": "Help"
            },
            "13": {
                "id": 13,
                "case": "first-letter",
                "*": "Diskuse k n\u00e1pov\u011bd\u011b",
                "subpages": "",
                "canonical": "Help talk"
            },
            "14": {
                "id": 14,
                "case": "first-letter",
                "*": "Kategorie",
                "canonical": "Category"
            },
            "15": {
                "id": 15,
                "case": "first-letter",
                "*": "Diskuse ke kategorii",
                "subpages": "",
                "canonical": "Category talk"
            }
        }
    }
}