The educational field is traditionally characterized by a distinction between general and special education in educational practice, theory and research. Especially in cross-professional collaborative processes related to inclusion, it becomes evident that the professionals represent different perspectives and positions with different roles, functions and main goals. Based on a research project in Denmark which examines how the collaboration of professionals constitutes in- and exclusion processes, we compare different understandings of aims and problems in the work with inclusion in collaborative school practice with the current models of inclusive education and special education represented in international literature. Our findings show that understandings of problems related to inclusive school development are mainly directed towards strategies targeting and compensating the needs of the student but seldom involve changing the professional practice of teachers and other educators, including their collaboration. Based on this, we argue -- and present a framework to support -- that inclusive school development involves a process of transforming general and special education into inclusive education, which requires changes in content, teaching methods, approaches, structures, and strategies in education. In order to succeed, classroom practice is only one sub-practice among many sub-practices in a school practice that needs to be transformed.