Scriptlets
From OpenCms Wiki
Scriptlets are just JSP files that are composed using regular Java code instead of taglib code. Note that one doesn't exclude the other, so you can even use a mix of the two.
Choosing between scriptlet code and taglib code is usually just a matter of preference, and a slight mix is not uncommon.
At the start of a scriptlet, you will typically find some kind of CmsJspActionElement and a CmsObject. These two (the CmsObject in particular) are often the central corner stones from which you can access many of OpenCms' features.