From LabVIEW Wiki
VI Scripting refers to the ability to read, generate and edit LabVIEW source code programatically. It is exposed as a series of classes in the VI server hierarchy whose properties and methods allow to read or change a diagram.
Scripting is useful for generating or editing VIs automatically based on simpler configurations. Examples of scripting include the code generated by Express VIs, the code generated for LVOOP accessor VIs and the code generated by the NI Vision Builder.
Because scripting requires recompiling the VI and may break it, you can not run scripting code on a VI which is reserved for running.
Because scripting has the potential to be dangerous, it is not available with LabVIEW. You can download its installer here.