Starting from s-expressions.

Take s-expressions. They allow elegant representation of nested list structures.

(this-is
    lisp-style
    (an-item another-one (item-3A item-3B) last-item))

In s-exp based languages, the first element usually indicates how to interpret the rest of a list...

(defun factorial (x)
    (if (zerop x)
        1
        (* x (factorial (- x 1)))))

... except when it does not. In the following example, the list of numbers doesn't begin with an element that would indicate "this is a list of number". You're directly inside the content, because of the quote.

(find 1 '(5 9 1 2))

Elements are separated by whitespace characters, which means elements themselves cannot contain whitespace characters. But we can modify the notation to allow them, simply using a comma as separator. It's now a mix of CSV and s-exp.

(this is,
    csv style,
    (an item, another one, (item 3A, item 3B), last item))

That reads better. There's still something bothering me though: items are anonymous. Take the following list of lists.

(
    ("John", "Paul",   male,   38),
    ("Ann",  "Mary",   female, 92),
    ("Kate", "Wilson",         24)
)

Which is the family name? What does the number represent? How about the third item? In many languages, either the first element of the list indicates how to interpret it, or another element (outside of the list) does, if the list is quoted. But borrowing from Smalltalk syntax, we can be more explicit.

(
    FamilyName: "John" GivenName: "Paul"   Gender: male   Score: 38,
    FamilyName: "Ann"  GivenName: "Mary"   Gender: female Score: 92,
    FamilyName: "Kate" GivenName: "Wilson"                Score: 24
)

Well, nothing spectacular, but from now on this will be our syntax here at [BLACK:TIGER:]. Both data and code are represented using this notation.

(
    name: "Max"
    species: "Dog"
    age: 4
    friends: (
        name: "Isidore" species: "Cat",
        name: "Jet Li" species: "Super Cat"
    )
)

This structure about my dog translates directly to the following JSON:

[
    {
        "name": "Max",
        "species": "Dog",
        "age": 4,
        "friends": [
            {
                "name": "Isidore",
                "species": "Cat"
            },
            {
                "name": "Jet Li",
                "species": "Super Cat"
            }
        ]
    }
]