There was no talk; it was an unconference.

I'll try to retell x264's story here...

Japan has long had a community of x264 developers and users, but for a long time they largely remained insular and didn't make much active effort to push their patches upstream. This wasn't out of maliciousness; there were many reasons.

The language barrier was a big problem -- less so that they didn't know English, but moreso that they didn't feel confident with it. In reality, we found the Japanese contributors to have way better English than they thought they did. People are often embarrassed or scared to use a language they're not confident with, and they worry about making mistakes and looking bad. Make them comfortable.

Note that this is especially an issue with Japan. In my experience, Japanese tend to be (typically) much less confident in their English despite equal or greater skill. This might be in part because the school system typically doesn't emphasize much 'real-time' conversational English.

This problem is more general than just language; open source IRC channels and mailing lists can be intimidating, and people (often rightly) suspect that they'll be mocked for making mistakes, so they just don't bother.

As is common in many non-English-speaking countries, the Japanese have many of their own tools and methods of communication that are unique to Japan. In this case, they had an ongoing x264 thread on 2ch. A friend of mine from the x264 user community offered to help. He was multilingual, able to speak near-perfect English and Japanese, along with many other languages. Using his translations, I answered questions for a few weeks on the 2ch thread.

Eventually it became somewhat obvious that one of the people posting in the thread was a Western developer; the Japanese jokingly called it the 'Black Boat incident', a reference to the arrival of Commodore Matthew Perry's fleet at Japan in 1853 (see http://en.wikipedia.org/wiki/Black_Ships). We convinced a few to drop by our IRC channel; we invited them, noting that difficulty with English was not a problem, and we had a Japanese speaker who they could converse with directly anyways.

A few came, some contributed patches, and a few stuck around; we now even have a small community of Japanese users who hang out in the main channels. One of them noted later that his (written) conversational English had improved vastly just by being on IRC for a few months and was now much more fluent.

Put simply, cultural and language barriers reduce peoples' confidence in communicating. They can also result in misunderstandings; open source developers, for example, tend to have a very blunt style of communication. In the best cases, this can mean they will ignore their own ego and debate decisions on technical merits, without pleasantries. In the worst cases, this can mean rudeness, intolerance, and general dickishness. Especially coming from a culture more heavily based around politeness, this can be daunting.

If you want to welcome a foreign community of developers, you should try to (list certainly not complete):

1. Have someone who speaks their language, so they can feel confident that they have someone to speak to even if they aren't confident in their English skills.

2. Contact them first; don't rely on them to come to you.

3. Be friendly and welcoming. If you have to, mute That Guy who insists on being rude and obnoxious. Mocking grammar errors or being needlessly blunt are quick ways to make people feel incredibly unwelcome. They probably speak your language much better than you speak theirs!

4. Give them extra help -- don't treat them like Just Another Patch Contributor. Your goal here is not just to integrate their changes, but to gain a connection to their developer community. "Patch rejected, I don't like it" is not a way to gain friends.

5. I really shouldn't have to say this, but apparently (from experience) I have to: seriously -- don't be a racist asshole. Particularly if you're inviting people to an IRC or high-traffic mailing list, there are often people (including devs!) who will make all sorts of insensitive comments. This needs to not happen. Yes, this means no stupid jokes about "roneriness" or Indian tech support.

Yes, this also means no stereotyping. Just because they're Japanese doesn't mean they want to talk about Naruto, and just because they're Chinese doesn't mean they really like General Tso's Chicken. I know you really love Korean culture, but just because they're Korean doesn't mean they want to talk about Girls' Generation and Starcraft. Don't treat someone from a different country as if they're some specimen under a microscope either. In short, avoid othering. Making people feel as if they are different and not wanted is a quick way to make them not want to come back.