New answers tagged software
Wikipedia lists a selection of computer-assisted translation tools. You might also try to search your favourite search engine for "translation workstation" or "translator's workstation".
I recommend the book World-Building -- A writer's guide to constructing star systems and life-supporting planets, by Stephen L. Gillett. The author has a PhD in geology, and so he covers topics like plate tectonics, water and air, magnetic fields, colors, etc. The book also covers various aspects of planets and stars, orbits, gravity, seasons and tidal ...
Celtx is free, mostly open-source (it has a nonstandard license and there are some closed components) and very good. It does script formatting, plus a bunch of other organisational stuff (keeping track of characters, storyboards). I haven't used it for a while, but I found it very intuitive and so on. There is even some collaborative stuff built into it, ...
Final Draft is the most common one that I know of. But it's not free. Once you've finished your script and want industry people to read it, you'll need a recognized script formatting program like Final Draft or Movie Magic.
I have written a tool for my own use that will almost do what you want, but I hadn't thought that anyone else would use it, so it is a bit rough around the edges, it would only take me a couple minutes to add wdiff to it, but it assumes POSIX (unix/linux/OSX) is written in perl, has no documentation, and the command syntax is arcane. Would you like to try it ...
Have you tried Scrivener? I haven't used it for screenwriting, but it looks like it's got a great tool for it. It's not open source, but $45 is fairly cheap.
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