Jessub generates MaxL scripts based on templates with placeholders for dynamic values that can be filled in with values from the current date, relative date, or elsewhere. It can be a convenient way to update substitution variables without the pain of writing your own logic for what happens when you need to wrap a year or month or day of week or whatever else.
You can check out the original announcement/description and view the code repository. Licensed
Original announcement here. Google code repository is here. Licensed under Apache Software License version 2.