Edit in JSFiddle

var json = {
  "name": "Internet hallintanäkökulma",
  "children": [
    {
      "name": "Internet Corporation for Assigned Names and Numbers (ICANN)",
      "children": [
        {
          "name": "Internet Assigned Numbers Authority (IANA)",
          "children": [
            {
              "name": "African Network Information Centre(AfriNIC)"
            },
            {
              "name": "American Registry for Internet Numbers (ARIN)"
            },
            {
              "name": "Asia-Pacific Network Information Centre (APNIC)"
            },
            {
              "name": "Latin America and Caribbean Network Information Centre (LACNIC)"
            },
            {
              "name": "Réseaux IP Européens Network Coordination Centre(RIPE NCC)"
            }
          ]
        },
        {
          "name": "DNS root zone"
        }
      ]
    },
    {
      "name": "Internet Architecture Board (IAB)",
      "children": [
        {
      "name": "Internet Engineering Task Force (IETF)",
      "children": [
        {
          "name": "Internetin standardointi (RFC)"
        }
      ]
    },
    {
      "name": "Internet Research Task Force (IRTF)",
      "children": [
        {
          "name": "Internetin kehittämistä tutkimuksella"
        }
      ]
    }
      ]
    },
    {
      "name": "Internet Society (ISOC)",
      "children": [
        {
          "name": "Tavoitteena taata Internetin avoin kehitys ja pitää se saatavilla kaikille"
        }
      ]
    },
    {
      "name": "Internet Governance Forum (IGF)",
      "children": [
        {
          "name": "Subject area initiatives"
        },
        {
          "name": "Regional initiatives"
        },
        {
          "name": "National initiatives",
          "children": [
            {
              "name": "Finland IGF"
            },
            {
              "name": "jne."
            },
            {
              "name": "Foorumi Internetin hallintoon liittyvään keskusteluun"
            }
          ]
        }
      ]
    },
    {
      "name": "Institute of Electrical and Electronics Engineers (IEEE)",
      "children": [
        {
          "name": "Esim. linkkikerroksen standardointia (Ethernet IEEE802.3 ja WLAN IEEE802.11)"
        }
      ]
    }      
  ]
}

;

var margin = {
    top: 20,
    right: 20,
    bottom: 20,
    left: 130
},
width = 1600- margin.right - margin.left,
    height = 800 - margin.top - margin.bottom;

var i = 0,
    duration = 750,
    root;

var tree = d3.layout.tree()
    .size([height, width]);

var diagonal = d3.svg.diagonal()
    .projection(function (d) {
    return [d.y, d.x];
});

var svg = d3.select("body").append("svg")
    .attr("width", width + margin.right + margin.left)
    .attr("height", height + margin.top + margin.bottom)
    .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

//d3.json(jsonFlares, function(error, flare) {
var root = json;
//root = flare;
root.x0 = height / 2;
root.y0 = 0;

function collapse(d) {
    if (d.children) {
        d._children = d.children;
        d._children.forEach(collapse);
        d.children = null;
    }
}

root.children.forEach(collapse);
update(root);
//});

d3.select(self.frameElement).style("height", "800px");

function update(source) {

    // Compute the new tree layout.
    var nodes = tree.nodes(root).reverse(),
        links = tree.links(nodes);

    // Normalize for fixed-depth.
    nodes.forEach(function (d) {
        d.y = d.depth * 180;
    });

    // Update the nodes…
    var node = svg.selectAll("g.node")
        .data(nodes, function (d) {
        return d.id || (d.id = ++i);
    });

    // Enter any new nodes at the parent's previous position.
    var nodeEnter = node.enter().append("g")
        .attr("class", "node")
        .attr("transform", function (d) {
        return "translate(" + source.y0 + "," + source.x0 + ")";
    })
        .on("click", click);

    nodeEnter.append("circle")
        .attr("r", 1e-6)
        .style("fill", function (d) {
        return d._children ? "lightsteelblue" : "#fff";
    });

    nodeEnter.append("text")
        .attr("x", function (d) {
        return d.children || d._children ? -10 : 10;
    })
        .attr("dy", ".35em")
        .attr("text-anchor", function (d) {
        return d.children || d._children ? "end" : "start";
    })
        .text(function (d) {
        return d.name;
    })
        .style("fill-opacity", 1e-6);

    // Transition nodes to their new position.
    var nodeUpdate = node.transition()
        .duration(duration)
        .attr("transform", function (d) {
        return "translate(" + d.y + "," + d.x + ")";
    });

    nodeUpdate.select("circle")
        .attr("r", 4.5)
        .style("fill", function (d) {
        return d._children ? "lightsteelblue" : "#fff";
    });

    nodeUpdate.select("text")
        .style("fill-opacity", 1);

    // Transition exiting nodes to the parent's new position.
    var nodeExit = node.exit().transition()
        .duration(duration)
        .attr("transform", function (d) {
        return "translate(" + source.y + "," + source.x + ")";
    })
        .remove();

    nodeExit.select("circle")
        .attr("r", 1e-6);

    nodeExit.select("text")
        .style("fill-opacity", 1e-6);

    // Update the links…
    var link = svg.selectAll("path.link")
        .data(links, function (d) {
        return d.target.id;
    });

    // Enter any new links at the parent's previous position.
    link.enter().insert("path", "g")
        .attr("class", "link")
        .attr("d", function (d) {
        var o = {
            x: source.x0,
            y: source.y0
        };
        return diagonal({
            source: o,
            target: o
        });
    });

    // Transition links to their new position.
    link.transition()
        .duration(duration)
        .attr("d", diagonal);

    // Transition exiting nodes to the parent's new position.
    link.exit().transition()
        .duration(duration)
        .attr("d", function (d) {
        var o = {
            x: source.x,
            y: source.y
        };
        return diagonal({
            source: o,
            target: o
        });
    })
        .remove();

    // Stash the old positions for transition.
    nodes.forEach(function (d) {
        d.x0 = d.x;
        d.y0 = d.y;
    });
}

// Toggle children on click.
function click(d) {
    if (d.children) {
        d._children = d.children;
        d.children = null;
    } else {
        d.children = d._children;
        d._children = null;
    }
    update(d);
}

.node {
    cursor: pointer;
}
.node circle {
    fill: #fff;
    stroke: steelblue;
    stroke-width: 1.5px;
}
.node text {
    font: 10px sans-serif;
}
.link {
    fill: none;
    stroke: #ccc;
    stroke-width: 1.5px;
}