A system is described in which multiple companies can securely collaborate on a design or other project, while one company can still protect certain property, such as source code, from the other collaborating companies. The system includes an inter-company collaboration system that includes a set of resources residing on a set of one or more first utility servers maintained by a first company, an access control mechanism for controlling access to the set of resources, a first data storage mechanism, and a secure network connection between the set of utility servers and a second company. The system further includes an isolated system that includes a second set of servers, a second data storage mechanism that includes a first portion that contains data shared with the collaboration system and a second portion that contains data private to the isolated system, and a second access control mechanism to control access to the second set of servers to only individuals associated with one company.