Clear and effective technical communications are needed to keep the team in synch and to allow individuals with key knowledge to apply that knowledge where it is needed. One tenet of the open source community is that techincal communications should take place in public forums.
Mailing lists are the backbone of open source communications.
Beyond that, open source projects need support for precisely communicating technical details and for group decision-making. Version Control, Document Management, and Distribution Every software development project needs version control. Open source projects need strong and flexible support for many concurrent developers working on overlapping sets of files. Open source projects also need standard templates for design documents, technical documentation, and end user documentation. A well organized web site is required to distribute these documents.