I started the Go Study Group and Athens both about 6 months ago. I did each for super different reasons, but I wanted both to have strong communities. The people are what keeps these communities alive. Not me, not the technology, nothing else. It's the people. And that's why I'm so insistent on strong communities.
I've been part of lots of OSS communities - as a leader and as a member - and each one has either lifted me up or ground me down. I'm at a point in my career now where I can tell pretty quickly which type of community it's gonna be for me. Like after reading a few issues or doing a PR or two.
So with that experience, here's what a strong community is to me:
I went into detail on a lot of this in the Athens project with a "philosophy document".
There's no way I can sum up all those things in that list above, but I want to be able to say something to newcomers to whatever thing to basically say: "you're welcome here, and we'll do everything we can to make it nice here."
So I say this: "absolutely everybody is welcome"
I don't have some grand story of how I came up with this catch phrase or anything, I just feel like it sums up that list above (by the way I know it doesn't technically come close :P).
I use this all the time to say: "Hey folks! You're welcome to join us. We're inclusive, but we're more too. Someone is gonna be there to greet you and help you. You're not gonna be judged. You're not gonna have to run some huge gauntlet just to get started or prove yourself. We're happy you joined and you're not different than us. We have work to do and we want you to do it with us."
If you want to join either/both of these communities, here's how: