1. Introduction

People collaborate to tackle problems which are larger and more complex than any individual's capabilities.
However, not every collaboration can go beyond simple addition of individual works; a few Great Groups[OG] perform extraordinary works, while others do "good" jobs.
From time to time, there emerges a group of people who work together to achieve amazing feats.
These groups are usually relatively small, highly motivated and stocked with very smart people.
They achieve more than anyone could have expected.
Their legacy includes such groups as Edison's researchers, Walt Disney's animation team and the members of the Manhattan Project.
When writing about such groups, Warren Bennis coined the apt term "Great Groups."[OG] The awesome creativity and thinking power of Great Groups makes them very desirable.
If the inner workings of such groups could be examined and understood it might be easier to create environments more hospitable to the creation of Great Groups.

People collaborate to tackle problems which are larger and more complex than any individual's capabilities.
However, not every collaboration can go beyond simple addition of individual works; a few Great Groups[OG] perform extraordinary works, while others do "good" jobs.
Collaborative work, by its nature, comes with several overheads; e.g. communication cost in order of squared number of participants[MMM], management cost to organize individual activities into common goals, and morale problem especially when collaborators become anonymous.
Collaborative works can therefore be less than simple addition of individual works.

A successfull group does not only organize individual works toward one goal effectively with minimal overheads, but also provides extra capabilities to individual participants.
Seven Great Groups in Organizing Genius, namely Disney, PARC and Apple, 1992 Clinton campaign, Skunk Works, Black Mountain College, and Manhattan Project, are good examples of Great Groups.
They are groups of great talents and their works are more than sum of individual great talents.

All of the seven Great Groups happened in pre-internet era.
We will describe Linux community as a different type of Great Group emerging in this internet era, and also discuss a new model of Great Groups in future with referring to concepts and technologies introduced in the DLC class.