Adobe’s HTML Template Language (more widely known as HTL), is the preferred method to write code for Adobe Experience Manager components and templates. From Adobe’s HTL overview page: “a highly productive enterprise-level web framework that increases security, and allows HTML developers without Java knowledge to better participate in AEM projects” & “the HTML Template Language helps to achieve increased security and development efficiency.” It was introduced in AEM 6.0. How do you use it, if you’ve never had to before?
That is where Feike Visser, from Adobe comes in. He has written a 5 part series (HTML Template Language (HTL) introduction) that explains how to use HTL. His articles contain “code samples, and compares them to the older ways of component development via JSP”, along with several other things. If you don’t know how to use HTL, then this is where you need to start.
And if you see Sightly anywhere, just remember that is the old name for HTL. They are the same.