Grouped horizontal bar chart.

This is an example of a horizontally grouped bar chart. It allows you to easily see the difference between different series of data.

<!DOCTYPE html>
<meta charset="utf-8">
<style>

/*
.chart rect {
  fill: steelblue;
}
*/
.chart .legend {
  fill: black;
  font: 14px sans-serif;
  text-anchor: start;
  font-size: 12px;
}

.chart text {
  fill: white;
  font: 10px sans-serif;
  text-anchor: end;
}

.chart .label {
  fill: black;
  font: 14px sans-serif;
  text-anchor: end;
}

.bar:hover {
  fill: brown;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

</style>
<svg class="chart"></svg>
<script src="https://d3js.org/d3.v3.min.js"></script>
<script>

var data = {
  labels: [
    'resilience', 'maintainability', 'accessibility',
    'uptime', 'functionality', 'impact'
  ],
  series: [
    {
      label: '2012',
      values: [4, 8, 15, 16, 23, 42]
    },
    {
      label: '2013',
      values: [12, 43, 22, 11, 73, 25]
    },
    {
      label: '2014',
      values: [31, 28, 14, 8, 15, 21]
    },]
};

var chartWidth       = 300,
    barHeight        = 20,
    groupHeight      = barHeight * data.series.length,
    gapBetweenGroups = 10,
    spaceForLabels   = 150,
    spaceForLegend   = 150;

// Zip the series data together (first values, second values, etc.)
var zippedData = [];
for (var i=0; i<data.labels.length; i++) {
  for (var j=0; j<data.series.length; j++) {
    zippedData.push(data.series[j].values[i]);
  }
}

// Color scale
var color = d3.scale.category20();
var chartHeight = barHeight * zippedData.length + gapBetweenGroups * data.labels.length;

var x = d3.scale.linear()
    .domain([0, d3.max(zippedData)])
    .range([0, chartWidth]);

var y = d3.scale.linear()
    .range([chartHeight + gapBetweenGroups, 0]);

var yAxis = d3.svg.axis()
    .scale(y)
    .tickFormat('')
    .tickSize(0)
    .orient("left");

// Specify the chart area and dimensions
var chart = d3.select(".chart")
    .attr("width", spaceForLabels + chartWidth + spaceForLegend)
    .attr("height", chartHeight);

// Create bars
var bar = chart.selectAll("g")
    .data(zippedData)
    .enter().append("g")
    .attr("transform", function(d, i) {
      return "translate(" + spaceForLabels + "," + (i * barHeight + gapBetweenGroups * (0.5 + Math.floor(i/data.series.length))) + ")";
    });

// Create rectangles of the correct width
bar.append("rect")
    .attr("fill", function(d,i) { return color(i % data.series.length); })
    .attr("class", "bar")
    .attr("width", x)
    .attr("height", barHeight - 1);

// Add text label in bar
bar.append("text")
    .attr("x", function(d) { return x(d) - 3; })
    .attr("y", barHeight / 2)
    .attr("fill", "red")
    .attr("dy", ".35em")
    .text(function(d) { return d; });

// Draw labels
bar.append("text")
    .attr("class", "label")
    .attr("x", function(d) { return - 10; })
    .attr("y", groupHeight / 2)
    .attr("dy", ".35em")
    .text(function(d,i) {
      if (i % data.series.length === 0)
        return data.labels[Math.floor(i/data.series.length)];
      else
        return ""});

chart.append("g")
      .attr("class", "y axis")
      .attr("transform", "translate(" + spaceForLabels + ", " + -gapBetweenGroups/2 + ")")
      .call(yAxis);

// Draw legend
var legendRectSize = 18,
    legendSpacing  = 4;

var legend = chart.selectAll('.legend')
    .data(data.series)
    .enter()
    .append('g')
    .attr('transform', function (d, i) {
        var height = legendRectSize + legendSpacing;
        var offset = -gapBetweenGroups/2;
        var horz = spaceForLabels + chartWidth + 40 - legendRectSize;
        var vert = i * height - offset;
        return 'translate(' + horz + ',' + vert + ')';
    });

legend.append('rect')
    .attr('width', legendRectSize)
    .attr('height', legendRectSize)
    .style('fill', function (d, i) { return color(i); })
    .style('stroke', function (d, i) { return color(i); });

legend.append('text')
    .attr('class', 'legend')
    .attr('x', legendRectSize + legendSpacing)
    .attr('y', legendRectSize - legendSpacing)
    .text(function (d) { return d.label; });

</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

https://d3js.org/d3.v3.min.js