list of free screenwriting software downloads

All these sofware listed here are free downloads for trying only.  Once you've actually used the software and like your practice run, you can buy.  It all boils down to what features you like that suit your own, personal taste.  For example, you may not like how a drop down menu is presented in one software, while you like where the drop down menus are located in another.  Price is also a factor.  The expensive ones, at least $100, are Final Draft and Movie Magic.  Here is a list of free screenwriting software downloads:

Movie Magic

Final Draft

Sophocles Screenwriting Software 1.1 

Hollywood Screenplay

Scriptware

Page2Stage

Screenwriting Index

Amazon