We actually have a post in the pipeline that discusses how we put together our modest-budget multi-projector worship package. But, I found this and thought it might be useful too.
The online seminar centers on ProVideoPlayer, made by the same folks who make ProPresenter, a popular Mac worship service presentation software.
ProVideoPlayer allows you to use multiple computers to present unified clips using all the displays as one. Each computer is responsible for playing it’s part of the image, not the whole. It even allows you to adjust the image for the displays’ bezels.
Are you using ProVideoPlayer? If so, what are doing with it?