CiviCRM has an active and vibrant open source community. As CiviCooP we participate actively in the community. You can find us on stack exchange answering questions, on chat.civicrm.org.
Erik Hommel is elected in the community council. Jaap Jansma does triage of the bug reports. We have organized meetups and CiviCons.
When we do custom development for our clients we always share our work with the wider community.