I like this idea. I think we already have a space that works pretty well for this kind of discussion of software features—Phabricator—so the two missing ingredients are (1) a policy or norm that product teams should create fairly detailed tasks describing their plans before starting work on a user-facing project and (2) a Phab project which would contain only this type of large, user-facing project, so users who want to comment on big ideas don't have to wade through engineering-focused tasks to find them.

Is phabricator widely used by either the editing or reading populations these projects would impact?

I think the canonical place for concepts of software projects aiming to be deployed in Wikimedia should be mediawiki.org.

• The project will need a communication page anyway. The initial concept page can be the logical seed, the first step.
• Wiki pages are better than Phabricator tasks for collaborative editing, formatting, and handling questions in the Discussion page.
• mediawiki.org is a multilingual wiki, and these pages could be made translatable if desired.

The Phabricator project or epic task could be an item in the checklist to enter the Plan stage, but not a requirement to work in the Concept stage.

@Keegan, this task is related to community engagement + Concept stage, therefore I think we need to schedule it for Liaisons-February-2016.

I'm starting work on T123611, which should outline scenarios where a private plan might be desirable and potential walk-throughs of either not making it private at all from the start, or provide for planning on when and how to make the thing public as early as possible. Completing that task should theoretically complete this one, since the question (in my mind) isn't "When should a plan be public?" but "When should a plan not be public?" since that should not be the norm.

Removing Team Practices Group for now. If you need something specific from the TPG, we suggest you consider using a template along the lines of the example requests here:

https://www.mediawiki.org/wiki/Team_Practices_Group/How_To_Engage_With_TPG

T144625: First review of the Technical Collaboration Guidance by Foundation Product teams and most active technical volunteers is still open. Pushing this task to the next quarter.

In T118231#2925922, @Qgil wrote:

T144625: First review of the Technical Collaboration Guidance by Foundation Product teams and most active technical volunteers is still open. Pushing this task to the next quarter.

It would be also nice if any software project willing to be prioritized required a public implementation plan (ie. don't circumvent the RfC process for WMF software). I think lately we are getting better at that but it would still nice if it was called out explicitly.