.FSL File Extension
File TypeForm•Z Script
What is an FSL file?
Script written in the form•Z scripting language (FSL), a plugin development language for form•Z 3D solids and surfaces modeling software; uses syntax similar to the C programming language but is more simplified; can use functions specified in the FSL API.
When a script is complete, it is compiled into a binary representation in a .FSB file, which is read by form•Z.