The <radialGradient> HTML5 tag is used to draw SVG Gradients. Yes, modern browsers support it.
The following is the HTML5 version of an SVG example that would draw an ellipse using the <ellipse> tag and would use the <radialGradient> tag to define an SVG radial gradient. Similar way you can use the <linearGradient> tag to create SVG linear gradient.
<!DOCTYPE html>
<html>
<head>
<style>
#svgelem{
position: relative;
left: 50%;
-webkit-transform: translateX(-40%);
-ms-transform: translateX(-40%);
transform: translateX(-40%);
}
</style>
<title>SVG</title>
<meta charset="utf-8" />
</head>
<body>
<h2 align="center">HTML5 SVG Gradient Ellipse</h2>
<svg id="svgelem" height="200" xmlns="https://www.w3.org/2000/svg">
<defs>
<radialGradient id="gradient" cx="50%" cy="50%" r="50%" fx="50%" fy="50%">
<stop offset="0%" style="stop-color:rgb(200,200,200); stop-opacity:0"/>
<stop offset="100%" style="stop-color:rgb(0,0,255); stop-opacity:1"/>
</radialGradient>
</defs>
<ellipse cx="100" cy="50" rx="100" ry="50" style="fill:url(#gradient)" />
</svg>
</body>
</html>