CiviCRM Community Forums (archive)

To address a few things that have come in comments:

Any mailing list for developer discussion will have public archives. This is a strong requirement.

In terms of the specific tool used for mailing-lists, civicrm.org currently uses both Sympa (eg civicrm-api) and Google Groups (eg civicrm-partner-program) about evenly. Both are quite serviceable for email-based usage. They have some trade-offs individually, e.g.

• Sympa can integrate with users and groups on civicrm.org. So you could manage mailing-list memberships the same way you handle newsletter or blog access. This is also nice from a dogfooding perspective, and we can come up with more interesting flows (eg autoenrolling partners and members into respective lists). Sympa is open-source.
• Google Groups provides a web interface for making posts. (There's some dispute about whether this interface is actually nice, but it does more than Sympa's.) Google Groups ties in a bit better with your Google/Gmail account.
• The visual layout in Google Groups has prettier styling, but the structure in Sympa is simpler (less busy).

If you feel the differences are important, feel free to comment in the survey or forum about how (and whether that would affect your vote).