I tend to describe the communities I organize as "welcoming." And, further, I demand that they be. In my mind, this can take many forms. Regulars might offer a friendly word of welcome to newcomers, members can invite others to join us, and so on. Those actions are definitely part of being welcoming, but there's something deeper there -- something more important.
When you feel "welcome" somewhere, you've perceived that there is a place for you; that the other people there acknowledge, accept and appreciate that you're there; that you're a part of the group, not an outsider. Welcomingness isn't a quality you can bestow on a community, or buy at Office Depot (although, name tags do make me feel more welcome!). If a community wants to be a welcoming community, its members must create that space.
So, how do we, as part of a community that strives to be welcoming, create space that can be comfortably occupied by others? Communities are built and held together by the words and deeds of its members. It is the collective body of all of our words and deeds that can either leave space for all types of people, or close them out, sending the message that certain people aren't welcome. And, in my experience, it can be the offhand comments and subtle rejections that send the loudest message.
Each one of us -- including myself, I'll be the first to admit it -- has accidentally sent messages of exclusion in the communities we care deeply about. As one myself who doesn't fit the usual tech mold, I often perceive that I'm an outsider. Small things easily remind me that I'm an exotic species too rare to even count ("There just aren't any female programmers!"). I know it's an exaggeration of reality and made for effect, often even a lamentation, but it has the side-effect of making me feel invisible. If you want there to be more diversity in our community, please don't close up the space new and different individuals might soon occupy.
Life is all just practice. In this community, let's practice being more welcoming by speaking and acting in ways that don't exclude people. When we hear or see our fellows speaking or doing otherwise, let's take these as opportunities for discussion among friends, and for welcoming one another to grow. Let's work together to build a better community.