XWiki's advanced features for structuring data and scripting in wiki pages make it suitable for developing applications of various sizes, for various needs. The wiki principle make all these applications collaborative by default, while the multiple UI configuration options and permission system allow to show as much or as little of it as needed for the specific case . In this talk I will explain the usage of XWiki through the angle of comparing its usage with the development of applications from scratch. I will explain and demo the various features of the XWiki platform and how they can be assembled together to create applications and show some examples of such work that was done for professional accounts (e.g. https://nosdemarches.gouv.fr ).