This document discusses collaboration in digital humanities projects and infrastructure. It addresses whether humanists typically collaborate and how, examining modes like teaching, conferences, and online communities. True collaboration is defined as multi-disciplinary, co-authored work or lab-style projects with a common goal. Digital humanities requires collaboration between different domains like library science, computer science, and the humanities. Successful digital humanities infrastructure projects also require collaboration between researchers, users, institutions, and other stakeholders. The document outlines some challenges to collaboration, like different vocabularies between specialists, and the importance of trust, shared values and expectations, knowledge sharing, and intermediaries to bridge gaps.