Object-oriented computing is now an established technology for software development. However, a number of challenges must be met before the topic can claim to be fully mature. One of the most demanding challenges is posed by the move from single workstation environments to the more general case of a distributed system. The paper considers the impact of distribution on object-oriented computing. A number of important issues are raised, such as the need for a broader view of object-oriented computing and the requirement for flexible approaches to invocation. Problems relating to persistence and distribution transparency are also discussed. The importance of underlying system support for distributed object-oriented computing is stressed, and a case study of the Chorus/COOL environment is presented.