Add a new property to HtmlChart as well as Gauges to AutoResize on parent control size change. A precondition to this is Height and Width of the control must be set in percentages of the parent control.

To implement this we can either use window.onresize or ResizeObserver.

Reference

Reference 2

The scenario is the same web-page should render perfectly on all kind of devices(mobile, tablet, desktop, laptop, projector, and high-resolution TV etc.)

The Bar width is set using Size property for Minor tick. The Pointer Width is set using Size property of Pointer.

Now that the sizes for bar and pointers are fixed, we cannot change it with changing screen resolution.

SVG has the property for scaling itself based on the design size and actual size on the client (ViewPort Size).

If something like design width and design height property is added, it will be really helpful to scale the same control and use it on all kind of devices with resolutions ranging from 320 x 180 to 4K UHD displays.

The underlying Kendo Linear Kendo stopped rendering the track in 2014.3.1314 and, respectively, so does RadLinearGauge as of 2015.1.225

For example, the following snippet should render a wide, green, semi-transparent track, but it does not

			<telerik:RadLinearGauge ID="gauge" runat="server" Height="280">
				<Pointer Value="20">
					<Track Color="#5ca038" Opacity="0.5" Size="30" />
				</Pointer>
			</telerik:RadLinearGauge>

Workaround:

  1) Use   RenderAs="SVG".
  2)  Set 100% width to the gauge's wrapper prior the resizing
 
Use the solution below to make the control responsive:
     <table style="width: 100%;">
            <tr>
                <td>
                    <div style="width: 100%;" id="gauge"></div>
                    <telerik:RadLinearGauge runat="server" ID="RadLinearGauge1" RenderAs="SVG" Width="100%">
                        <Pointer Color="Gray" Size="10" />
                        <Scale Vertical="false" Min="0" Max="40">
                            <MinorTicks Size="20" />
                            <Ranges>
                                <telerik:GaugeRange Color="#D7E5D1" From="0" To="10" />
                                <telerik:GaugeRange Color="#EBE6D2" From="10" To="20" />
                                <telerik:GaugeRange Color="#F5D2D1" From="20" To="30" />
                            </Ranges>
                        </Scale>
                    </telerik:RadLinearGauge>
                </td>
            </tr>
        </table>
            <script type="text/javascript">
                var $ = $telerik.$;
                $(window).resize(function () {
                    $("#<%= RadLinearGauge1.ClientID %> > div")[0].style.width = "100%";
                    $find('<%= RadLinearGauge1.ClientID %>').get_kendoWidget().resize();

                });
            </script>

For the time being you can use the following workaround:

        <script>
            var pointerSize = 35;

            function pageLoad() {
                var gauge = $find("<%=rgEpmScorecard.ClientID%>");
                gauge._gaugeObject.options.scale.rangeSize = 25;
                gauge.repaint();
            }

        </script>
        <telerik:RadRadialGauge ID="rgEpmScorecard" runat="server" Skin="Metro" Height="99px" Width="100px">
            <Pointer Value="50" Color="Black">
                <Cap Size="0.5" Color="Black" />
            </Pointer>
            <Scale MajorUnit="10" Max="100" Labels-Visible="false" StartAngle="-45" EndAngle="225">
                <MajorTicks Visible="false" />
                <MinorTicks Visible="false" />
                <Ranges>
                    <telerik:GaugeRange Color="#ac1d23" From="0" To="16.67" />
                    <telerik:GaugeRange Color="#c26522" From="16.7" To="33.33" />
                    <telerik:GaugeRange Color="#d2b408" From="33.5" To="50" />
                    <telerik:GaugeRange Color="#b5be25" From="50.04" To="66.66" />
                    <telerik:GaugeRange Color="#0c833f" From="66.8" To="83.33" />
                    <telerik:GaugeRange Color="#0b6cb3" From="83.38" To="100" />
                </Ranges>
            </Scale>
        </telerik:RadRadialGauge>
        <script>

            var dataviz = kendo.dataviz,
                draw = dataviz.drawing,
                Path = draw.Path,
                DEFAULT_LINE_WIDTH = 0.5;

            kendo.dataviz.RadialPointer.fn._renderNeedle = function () {
                var that = this;
                var options = that.options;
                var minorTickSize = that.scale.options.minorTicks.size;
                var center = that.center;
                var needleColor = options.color;

                var needlePath = new Path({
                    fill: { color: needleColor },
                    stroke: { color: needleColor, width: DEFAULT_LINE_WIDTH }
                });

                needlePath.moveTo(center.x + that.radius - minorTickSize + pointerSize, center.y)
                          .lineTo(center.x, center.y - (that.capSize / 2))
                          .lineTo(center.x, center.y + (that.capSize / 2))
                          .close();

                return needlePath;
            }
        </script>

The following:

<telerik:RadLinearGauge runat="server" ID="RadLinearGauge1" width=100%></telerik:RadLinearGauge>

will result in the width being set as 100px

Label for the Gauge range in the RadGauge control.
Apart from the individual points, need ability to name the range.

You can do this with the Template property of the Label object

			<telerik:RadLinearGauge runat="server" ID="rlg1">
				<Scale Min="1" Max="4" MajorUnit="1">
					<Labels Template="#= getLabelText(value)#" />
				</Scale>
			</telerik:RadLinearGauge>
			<telerik:RadRadialGauge runat="server" ID="rrg1">
				<Scale Min="1" Max="4" MajorUnit="1">
					<Labels Template="#= getLabelText(value)#" />
				</Scale>
			</telerik:RadRadialGauge>
			<script>
				function getLabelText(e) {
					return "label for " + e;
				}
			</script>

For old versions the template can be set through the kendoWidget:

ASPX:

        <script>
            function setGaugeLabels(value) {
                switch (value) {
                    case -10:
                        return "Min: " + -10;
                        break;
                    case 35:
                        return "Max: " + 35;
                        break;
                    default:
                        return "Name: " + value;
                        break;
                }
            }
            function pageLoad() {
                var gaugeObj = $find("<%=RadLinearGauge1.ClientID%>")._gaugeObject;
                gaugeObj.options.scale.labels.template = "#=setGaugeLabels(value)#";
                gaugeObj.redraw();
            }
        </script>
        <telerik:RadLinearGauge runat="server" ID="RadLinearGauge1" Height="300px" Width="100px">
            <Pointer Value="11" Color="Green">
            </Pointer>
            <Scale Min="-25" Max="50" MajorUnit="15" MinorUnit="1">
                <Labels Format="{0} °C" />
                <Ranges>
                    <telerik:GaugeRange From="-25" To="-5" Color="Blue" />
                    <telerik:GaugeRange From="-5" To="15" Color="LightBlue" />
                    <telerik:GaugeRange From="15" To="30" Color="GreenYellow" />
                    <telerik:GaugeRange From="30" To="50" Color="Red" />
                </Ranges>
            </Scale>
        </telerik:RadLinearGauge>

It would be nice if RadGauges, the radial ones especially, could include a title element

Expose an additional property in RadGauge that controls the margin for the gaugeArea.

Implement autoscale functionality to RadGauge

As a workaround the width of the range placeholder can be set through the gaugeObject:
JavaScript:
		function pageLoad() {
			var gauge = $find("<%=RadRadialGauge1.ClientID%>");
			gauge._gaugeObject.options.scale.rangeSize = 30;
			gauge.repaint();
		}
		<telerik:RadRadialGauge runat="server" ID="RadRadialGauge1" Height="350px" Width="350px">
			<Pointer Value="220" Color="Black">
				<Cap Color="Gray" Size="0.1" />
			</Pointer>
			<Scale Min="120" Max="300" MajorUnit="30" MinorUnit="5">
				<Labels Format="{0} °C" Position="Outside" />
				<Ranges>
					<telerik:GaugeRange Color="Orange" From="150" To="190" />
					<telerik:GaugeRange Color="Green" From="190" To="230" />
					<telerik:GaugeRange Color="Red" From="230" To="300" />
				</Ranges>
			</Scale>
		</telerik:RadRadialGauge>

I would like to consider the ability to customise the labels for the GaugeRange items that may not be part of a numerical index. For example, you may have a 3 range gauge that is low (green) / medium (orange) / high (red). Currently there is no way of customising these values.

I believe this would be similar to what is currently done in the Slider control ( http://demos.telerik.com/aspnet-ajax/slider/examples/slideritems/defaultvb.aspx)

Add border and border appearance options like color, width and type for the RadGauge. Currently the background color of the RadGauge is set to the wrapper of the control. Improve that color so that it fits in with the border and the shape of the control.

Currently RadGauge has an option to turn on/off the animation when the chart is rendered through its transition property. If that property is set to true the requested feature will allow setting the speed/duration of the animation.