Hi @Admin Admin,
You can find it on the following page (you need to scroll down a bit to see the list with all pipes):
You can filter by category (which is based on functionality) from the left sidebar.
If you select a certain pipe you can tell by its definition whether it's a pipe developed by Atlassian or not. If the definition of the pipe starts with 'atlassian' (e.g. - pipe: atlassian/aws-s3-deploy:1.1.0) then it is an Atlassian-developed pipe. If it is not developed by Atlassian, there is a section Support on each pipe's page, that has more details on who to contact for support.