What are the different patterns and practices in Distributed Agile Development?

According to me the focus should be communication, in the case of distributed agile development
maximizing the available communication bandwidth is the key to the successful distributed teamwork or the Distributed agile development. There are many simple practices that a team can implement to improve their communication in different geographies. Minimize the overhead of setting up a meeting across locations by having a conference phone and projector easily accessible ideally in the team room for meetings. This allows the whole team to get together quickly regardless of their location. Teams can use Web conferencing software in conjunction with the projector to share applications across the whole team. Video conferencing, if available, is even better than voice conferencing, as participants are less likely to disengage. So this is one such practice, so what are the others, share your views,

Distribution of teams across time zones has far more impact than geographical distribution alone according to me. The significant time zone differences introduce communication blackouts into the team’s day during which part of the team is simply not available.

A time zone distribution of three or four hours is workable with the whole team sharing either morning or afternoon hours. Teams need to focus on making best use of this overlapping time, with meetings and pairing taking place during these core hours.

This will bring a very good agile development in the organization which has its workforce in different parts of the world.

I totally agree - face to face communication is preferable.

Anyway in case of a distributed team not only the key is communication, but the focus of communication on finding out the priorities and features set / deadlines balance according to client needs is critical as well.

Beside all that, a few tools should be at hand and efficiently used by each member of distributed team. I mean source control/ sharing, tasks assigning and tracking, planning and reaching milestones.

Regarding both communication and tools there should be some explicit agreements between team members about the main communication terminals, communication flows and flows content - to the point.

In other words - work process / production streamlining.

Distributed teams usually encounter more challenges and need more help to enable them to stick with the core practices employed by agile teams. Many distributed teams abandon key practices because they seem too hard. Having one person on the team who is committed to the coach role is vital in keeping a distributed team on the right path.

To me, there is no substitute for face to face communication particularly at the pivotal points in the project. At the beginning of the project teams should insist on colocation for the first few iterations which is very important. This allows team members to get to know each other and build rapport and trust. Even social events will do good where they'll come to know each other. And then the start of the project is also when many key decisions are made, this happens more effectively if the whole team is involved in making decisions and committing to them. Plan and budget for travel as part of your project.

If travel isn’t possible then expect longer ramp up time for the team and plan to employ other tactics.