Valuable links:

Community-Directories

http://www.ic.org/

http://ecovillage.org/

https://numundo.org/

Eurotopia Book, Directory of Intentional Communities and Ecovillages in Europe

Gift-networks

https://www.streetbank.com/

https://kindista.org/

http://www.heroesandfriends.com/

https://therooster.co/

http://karmatribe.com

https://openki.net/

yunity.org

noomap.info

ceptr.org

cooperacy.org

profeth.org

lighttribe.com

social magnetics

savita

bank of happiness

search & shar

Gift-Apps

https://www.beagift.net/

https://www.sharetribe.com/

Gift-economy

http://wiki.gifteconomy.org/Main_Page

https://charleseisenstein.net/money-gift-economics/ - Charles Eisenstein on gift-economy

https://moneyless.org/ - Life without money

Volunteering

http://wwoof.net/

http://www.workaway.info/

http://helpx.net/

http://kindmankind.net/

Learning Networks

http://swapaskill.com/ - Swapping skills

https://www.meetup.com/ - Local get-togethers

http://thepublicschool.org/

https://www.alternative-learning.org/ - Advocating alternatives to compulsory learning

Free online courses (small selection)

https://iversity.org/

http://www.openculture.com/

https://www.open2study.com/

Knowledge, Techniques, DiY

http://www.appropedia.org/ - the largest wiki for collaborative solutions in sustainability, appropriate technology, poverty reduction, and permaculture.

http://solution.ecovillage.org/ - Solutions from the ecovillage network

http://opensourceecology.org/ - Open Source Ecology

http://naturalhomes.org/ - Natural homes buildings

http://earthship.com/ - Earthship building

Sharing books

http://www.bookcrossing.com/

Free schools, unschooling

https://en.wikipedia.org/wiki/List_of_democratic_schools - List of democratic schools

https://davidgribble.co.uk/ - Democratic education pioneer David Gribble

http://sandradodd.com/unschooling and http://unschoolery.com/ - Unschooling

http://www.freire.org/ - Paulo Freire Institute

http://unerzogen.de/ - (in German) Unerzogen-Magazin

Free-shops

http://wiki.gifteconomy.org/Free_Shop

https://www.freecycle.org/ - Free shop via mailing list

https://www.google.com/maps/d/viewer?mid=13uceWaJ0AxLU8ATwX50zmakVVw8&ll=52.48055449641247%2C13.377830349999954&z=10 - Berlin map of give-boxes and free shops (great inspiration for other cities)

Community Building Tools

http://ctb.ku.edu/en - Community Tool Box is a collection of practical tools for community-building

https://community-canvas.org/ - Framework for building and participating in communities

http://www.group-games.com - Group games

http://wilderdom.com/games/ - Team building activities and games

http://wilderdom.com/teambuilding/ - Team building ressources

https://www.seedsforchange.org.uk/resources - Skills for working in groups, facilitation etc.

Collectives and cooperatives

http://cultivate.coop/ - Knowledge on cooperatives

https://www.uk.coop/ - Coop models from the UK

Food cooperatives

www.foodcoops.org - Food Coop Toolkit

http://foodcoops.de/ - for Germany

CSA (Community Supported Agriculture) Networks

http://urgenci.net/ - International network of CSA

https://www.solidarische-landwirtschaft.org/de/ - for Germany

http://reseau-amap.org/ - for France

https://www.localharvest.org/csa/ and http://www.cooperativegrocer.coop/ - for USA

Others

https://ecobasa.org/en/community-tours/traveling-tips/ - Travelling without money

https://transitionnetwork.org/ - Transition Town movement

http://www.shareable.net/ - Sharing movement

http://ouishare.net/en - Collaborative economy network

https://en.wikipedia.org/wiki/Commons and http://www.onthecommons.org/ - Commons

https://p2pfoundation.net/ - Peer-to-peer foundation

http://www.oya-online.de/ - (in German) OYA-Magazine: anders denken. anders leben

http://planetfriendly.net/ - Sustainable living

https://www.curbed.com/2016/9/22/13019420/urban-design-community-building-placemaking - 101 urban interventions to improve your city