I use Wordpad because my Microsoft word needs to be fixed.
Not sure if the little i do, should be even considered a "script". Mine is loose, I just write the dialogue and something to remember what to draw.
For example this is what i made on Wordpad today:
(P = panel)
"P1:Small ship flying from normal ship
P2: Luxury ship
"Woah, that's a luxury travel ship!
"This is a ship used for VIP travelers. Businessmen and Politicians"
P3:
"Doesn't that means they will have high security?"
P4:
"Look at that. Either they had an accident or..."
P5:
"...Someone else already attacked them."