Hugin

Hugin is an open source tool, designed to create panoramic images by joining together several photos. This tool is based on Panorama Tools, and produces great and speedy results.

Hugin's aim is clear: to be a simple and easy to use platform that can take a number of spectacular photographs and turn them into a seamless panorama image.

Hugin comes with a comprehensive interface where you can select images, crop them, and correct their perspective and exposure. To do this, the user must mark the control points in each image, that is, the common areas that are present in each of the different pictures.

If at first, Hugin seems a bit complicated, don't worry, there are several tutorials on the official where you can learn how to use it like a pro.