Bootstrap: Bootstrap is a free, open-source framework. It has a simple integration process. A developer can integrate Bootstrap with other frameworks in no time. Bootstrap is compatible with computers, laptops and mobile phones and is also compatible with all web browsers such as Chrome, Explorer, Firefox, and so on. It has extensive pre-styled components like alerts, button groups, dropdowns, breadcrumbs, navigation bar, progress bar, and so on. Bootstrap is highly customisable and can be customised as per the project needs.