This scripting language is not available by default any more. To use it you will need to edit the AllowUnstableWindowsFeatures in the screen-scraper.properties file.
screen-scraper uses ActiveState's ActivePerl library for scripts written in Perl. Using Perl within screen-scraper can only be done on a Windows platform, and requires that the ActivePerl runtime be installed.
screen-scraper will automatically detect if the ActivePerl runtime is installed, which you can see by selecting a script from objects tree in the workbench and clicking on the Language drop-down. If you don't see Perl in the list then the runtime needs to be installed.
The ActivePerl runtime can be downloaded from ActiveState's download page for free.
Java classes can be instantiated within a script using the CreateBean function. For example, the following script will instantiate a RunnableScrapingSession for the "Weather" scraping session (which is found in the default screen-scraper installation) and run it: