Software to create composite panoramic group

[danazoid]

I have heard recently of a company that creates its panoramic group photographs of 300 - 500 people without the use of staging.

Instead they use sofware to composite 300-500 individual shots (standing and seated) into a panoramic group photograph. I am not sure but it may involve a chroma key process.

I take similar group shots with the use of staging and a 5x4 film camera, I have to take 4 shots, scan and ps edit the negatives to ensure all people are looking the correct way with their best expression.

Do any members of this forum know of any software that would enable me to shoot in this way?