I keep hearing about javascript templating engines like knockoutjs or backbone recently. They all seem pretty cool but I was wondering if using such systems prevents good indexing of web pages.
Are the search engines' crawlers able to parse the javascript data? I thought it was bad practice to put the page's content in javascript as it was not parsed by some of these crawlers.
Many search engine crawlers now parse JavaScript and will pick up templated content. But there are literally hundreds of crawlers out there and some of the smaller ones still don't understand templates.
If you want full support then server rendered HTML is the only solution. If you're happy just being picked up by the big engines, googlebot, bingbot, baiduspider, etc then JavaScript client side templates can work. But you'll need to check who's picking them up..