How do I create a server-side template in Dart where I can set a different <title/> for each page?

Try out mustache, a Dart implementation of mustache templates, a widely used templating syntax, with implementations in a number of languages.

Here's an example:

import 'package:mustache/mustache.dart';

main() {
    var source = '{{#names}}<div>{{lastname}}, {{firstname}}</div>{{/names}}';
    var template = new Template(source);
    var output = template.renderString({'names': [
        {'firstname': 'Greg', 'lastname': 'Lowe'},
        {'firstname': 'Bob', 'lastname': 'Johnson'}
    ]});
    print(output);
}

The Dart team is currently focused on client side development, so many basic server-side features are missing in the core libraries. However take a look at pub, there are a number of community maintained packages available.

Also see this similar package: mustache4dart.