cottage industry

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A usually small-scale industry carried on at home by family members using their own equipment.
• noun A small, loosely organized, yet flourishing complex of activity or industry.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A job or occupation carried out at home or on a part-time basis.
• noun A small-scale industry, with relatively few employees or a limited customer base or low economic impact.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun small-scale industry that can be carried on at home by family members using their own equipment