While organisations recognise the advantages offered by global software development, there are many socio-technical barriers that affect successful collaboration in this inter-cultural environment. In this paper we present a review of the global software development literature where we highlight collaboration problems experienced by a cross-section of organisations in twenty-six studies. We also look at the literature to answer how organisations are over- coming these barriers in practice. We build on our previous study on global software development where we define collaboration as four practices related to agreeing, allocating, and planning goals, objectives, and tasks among distributed teams. We found that the key barriers to collaboration are geographic, temporal, cultural, and linguistic distance; the primary solutions to overcoming these barriers include site visits, synchronous communication technology, and knowledge sharing infrastructure to capture implicit knowledge and make it explicit.