Very interesting idea!
For others, here's what I understood from the About page: the "synthesizer" is not a musical one, it's algorithmic. You give examples of inputs and outputs you want, and it "synthesizes" a pipeline of shell command(s) to make that transformation.
Example:
Input: 1,2,3
Output: 123
Result:
# 1. Delete occurrences of ",".
tr -d ,
