Thanks for the question, @ih.
The Scripts section of the File Exchange is intended to share working scripts in the form of .jsl files. We hope these files will be useful in an of themselves.
The new JSL Cookbook is more of learning tool to show how to perform common tasks using JSL. The scripts in the Cookbook are a part of the post itself (not buried in a .jsl file) and will likely have to be customized to be useful.
I hope that makes some sense and that you find the new cookbook useful. I hope you'll contribute to it.
-Jeff
