Summary Privatization and marketization have been introduced in early education and care (ECEC) services in many countries with cost-efficiency as main motive. In the same time, cultural diversity in society has increased strongly, calling for policies to ensure equal opportunities for development and learning. A prominent response in many countries has been the introduction of early education programs for disadvantaged children to prevent early education gaps, raising the question to what extent privatization and marketization of ECEC are compatible with the public task of ensuring equal opportunities for young children. The present dissertation focused on the Dutch ECEC system as a case in point. After successive liberalization reforms, the Dutch ECEC system has become a hybrid system in which major public tasks, including foremost the prevention of early education gaps, are allocated to both private for-profit and private not-for-profit organizations. The leading questions of the current research were (1) whether in the context of system hybridity and increasing cultural diversification different types of ECEC organizations have emerged, and (2) whether these types of organizations differ in quality and coping with diversity and inclusion. In a series of qualitative and quantitative studies, different types of ECEC organizations were identified. These types of organizations were found to differ strongly in quality and inclusiveness. Socially engaged professional organizations, characterized by a strong focus on professionalism, high outreach to disadvantaged groups and endorsement of an emancipatory mission, outperformed the other types of organizations on virtually all indicators of quality and inclusiveness.