If you have a web browser and any text editor, you have everything you need to run JavaScript programs.
First, make an HTML file with a name like program.html:
<html>
<head>
<title>
Java Script Web Site
</title>
</head>
<body>
<pre><script src="script.js">
</script></pre>
</body>
</html>
.........................................................................................................
Then, make a file in the same directory with a name like script.js:
document.writeln('Hello, world!');
First, make an HTML file with a name like program.html:
<html>
<head>
<title>
Java Script Web Site
</title>
</head>
<body>
<pre><script src="script.js">
</script></pre>
</body>
</html>
.........................................................................................................
Then, make a file in the same directory with a name like script.js:
document.writeln('Hello, world!');