KB websites and resources around Atlassian

 Official Atlassian resources

Atlassian documentation

https://confluence.atlassian.com/alldoc/atlassian-documentation-32243719.html

Atlassian Webinars

https://www.atlassian.com/webinars/all?tab=all

Atlassian community

https://community.atlassian.com/

Atlassian Developer community

https://community.developer.atlassian.com/

Atlassian Developer documentation

https://developer.atlassian.com/

Atlassian Jira

https://jira.atlassian.com

Atlassian Marketplace

https://marketplace.atlassian.com/

Atlassian open source add-ons

https://ecosystem.atlassian.net/

Limited access :

https://partners.atlassian.com

https://enable.atlassian.com

Atlassian support 

* https://support.atlassian.com/ (you'll need a valid SEN...)

* for app developpers : https://ecosystem.atlassian.net/servicedesk/customer/portal/9