Yes. Celtx contains a screenwriting component, as does Five Sprockets.
In addition, some pay programs offer free demo versions with limitations, like a limited trial period or watermarked printing, for example.
Answer Index
script
scriptwriting
screenwriting
screenplay
formatting
terms
film
presentation
structure
business
writing
software
TV
WGA
Final Draft
guild
characters
length
credits
FDX
FDR
union
scene headings
dramatic theory
outlines
arbitration
adaptations
fountain
pdf
highland
producers
managers
Celtx
guru
Movie Magic
rights
agents
awards
pitching
short film
festival
iPhone
iPad
directors
prelap