There are many template languages available. The Simple Template Language distinct attributes are:
it is so simple it can be described as minimalist;
it enforces strict separation of presentation and logic, it is not possible to mix Python code into a template;
very easy to learn, high productivity, very fast.
Here there is a snippet:
<h2>Task Tracker</h2>
<div stl:repeat="task tasks"
xmlns:stl="http://xml.itools.org/namespaces/stl">
<h4>${task/title} (<em>${task/state}</em>)</h4>
<p>${task/description}</p>
</div>
I like to define STL as a descriptive language. It is amazing how many template languages are out there that allow to put Python code inside a template, and call it a feature.