This thesis concerns collaboration within the literacy project Bokstart, a project targeting families with young children. Public libraries can receive financial support from the Swedish Arts Council to run Bokstart. One requirement to receive funding is that the library collaborates with other sectors working on children's language development, such as child healthcare and preschool. Through our study, we aim to understand how collaboration between libraries and their partners looks after the project has ended, as well as identifying factors that facilitate or hinder collaboration. The empirical data consists of a document study of Bokstart reports and responses from a survey. Qualitative content analysis was used for analyzing the survey responses. The theoretical framework includes selected parts of Mattessich's collaboration theory and Danermark's theories on collaboration. We found that most libraries that received funding from the Swedish Arts Council continued with collaboration after the project ended, that the project led to an expanded collaboration and that the partners found various ways to collaborate. Facilitating factors for collaboration included: support from the manager, all partners having a shared vision and an identified common purpose for collaboration. Additional factors were that the collaboration group had agreements with each other and had both planned and informal meetings regularly. Hindering factors were, in addition to when the factors above were not enforced, lack of resources, issues with personal commitments, and problems that could arise due to the partners coming from different organizations. The findings from the analysis are consistent with existing research about collaboration.