Hi
Agile methodology is very popular in mostly small or medium sized companies where the requirement can change any time during the development process. In this methodology, there may or may not be availability of proper documents of requirement. In my last organisation I had worked on agile methodology. It was an in house project. This also happens when the companies create their own product, sometimes they done have the requirement clear at the beginning of the project. In that case, this type of methodology is helpful.
Thanks
Reena