Infinitely Nested List:

nested-list.html

<ul>
  <li>Item 1
    <ul>
      <li>Item 1.1
        <ul>
          <li>Item 1.1.1</li>
          <li>Item #1.1.2
            <ul>
              <li>Item 1.1.2.1</li>
            </ul>
          </li>
        </ul>
      </li>
      <li>Item 1.2</li>
    </ul>
  </li>
  <li>Item 2</li>
  <li>Item 3
    <ul>
      <li>Item 3.1</li>
    </ul>
  </li>
</ul>

nested-list.json

[
  {
    id: 1,
    name: 'Item 1',
    items: [
      {
        id: 2,
        name: 'Item 1.1',
        items: [
          {
            id: 3,
            name: 'Item 1.1.1',
            items: []
          },
          {
            id: 4,
            name: 'Item 1.1.2',
            items: [
              {
                id: 5,
                name: 'Item 1.1.2.1',
                items: []
              }
            ]
          }
        ]
      },
      {
        id: 6,
        name: 'Item 1.2',
        items: []
      }
    ]
  },
  {
    id: 7,
    name: 'Item 2',
    items: []
  },
  {
    id: 8,
    name: 'Item 3',
    items: [
      {
        id: 9,
        name: 'Item 3.1',
        items: []
      }
    ]
  }
]