Program text does not need to be placed in specific columns as on old punched card systems, and frequently ends of lines are insignificant.
Free-form languages allow a greater degree of flexibility and have fewer syntactic rules to learn, which could lower the entry barrier for beginners.
Rexx and its dialects ooRexx and NetRexx are mostly free-form, though in some cases whitespace characters are concatenation operators.
Structured languages exist which are not free-form, such as ABC, Curry, Haskell, Python and others.
Many of these use some variant of the off-side rule, in which indentation, rather than keywords or braces, is used to group blocks of code.