When it comes to a more or less sophisticated web site, a major headache is how to manage a numbre of similar pages with slightly different contents. Usually all those pages are generated on the server side by PHP, ASP, JSP or whatever else server-side engine. Server-side applications always use page layout templates, which are filled with a particular content on every client's request. If your web space comes from your local ISP along with the Internet access or you have a free hosting account somewhere else, normally you don't have the opportunity to run your own server-side applications on those premises. And if your web activity is not a vital part of your business, there's no point to apply for a paid hosting.
How does it look like? Like this tutorial pages.
Generally, the JST technique uses the only write() method of the document object. Since all state-of-the-art browsers do this method fine, the actual problem is writing a good HTML to be generated, that works in the same way in different browsers. However, if generated HTML is a lot sophisticated, some browsers (like Netscape versions prior 6) may get screwed up due to their buggy nature. Also the time of processing JST may go up drastically. So I find it reasonable to get rid of older browsers and provide a simplified code for Netscape 4.xx. A regular client sniffer (like those used for DHTML pages) is good for this purpose. I use this one, by the way.
All the examples are shown in pop-up windows. If your browser or some other program blocks pop-ups you may need to fix that problem first.
Either you did understand the above or not, please welcome to the next page anyway.