FATE 1e and FATE 2.0 are very similar, to the point of having basically the same rulebook layout as well as much of the same art. While I have a great deal of experience with 2nd edition FATE, I don't really know that much about 1st edition FATE and I'm having trouble seeing any real differences (besides the quality of the rulebook's writing and presentation) between first and second edition pdfs. I can see a bunch of seemingly random changes (no faceless minions in 2.0, all-but-no specific example section for aspects in 1e, no discussion on importance/value of negative aspects in 1e) but no real overall theme to the changes. What are the overall differences between 1st and 2nd edition?
In intent, the difference between 1 and 2 was mostly just to make it more readable/understandable and to take advantage of the fact that I'd gotten a little better with FrameMaker and had found some nice free clip art libraries.
I wish I was joking and that I could speak to some deeper design philosophy at work, but at that point in time, Fate was the engine for our home game, and the very act of writing it down was a learning process for us as we tried stuff, saw what worked and what didn't, and tried to share it. From that perspective, 1e (which was reasonably short lived) was kind of the rough draft for 2e (which is what most people saw). 1e, 2e (and, frankly, Don't Rest Your Head and Spirit of the Century) all show signs of what we were learning at the time. :)