>Ok, I see.
>
>I've always used the traditional waterfall method of the lifecycle, so this is new to me.
>
>
>1) What defines an iteration? Is it a period of time, or a series of changes?
A period of time, generally from one week to 30 days, but rarely more. You work on what you can get done in that time, then "release" it. The idea is to have working software, not lots documentation.

>2) Are changes released to the customer as they're done, or batched and released as a unit?
Could be either way. The key is to have the customer involved every step of the way and get updates frequently (daily is ideal) on what's happening.

>3) How does a project manager keep finished portions from being corrupted? As soon as someone
>starts changing a module, the potential to introduce bubgs is there.
Use something called "continuous integration". Code should not be checked in until it compiles and passes some unit testing. When it is checked in, a robot system checks out the code, builds it, runs unit tests, and maybe additional automated tests to help ensure the code works properly. While not everything can be automated, much of the process and tests can be. I am doing a session on continuous integration at German DevCon in November.

>4) How are change requests managed? Seems to me that makign changes in an interative model could be confusing.
I'll look at this using a Scrum, but XP is similar. An iteration in Scrum runs for 30 days and is called a Sprint. The product owner (typically the customer) posts a list of fixes that he wants done in the next 30 days. These are typically posted on a wall so everyone can see. Each team member takes one or two items, whatever they feel can be COMPLETED in 30 days, then get working on it. Every day, a 15 minute standup meeting, called a Scrum, is held where each team member answers three questions. 1. What did you do yesterday? 2. What will will do today? 3. What's standing in your way from getting it done? Any additional discussions are done later. The project manager's job is to remove any obstacles that are stopping people from working. At the end of the Sprint, a demo of new functionality is done and the code is "released".

I did a presentation on Agile development last year at Southwest Fox. Sometime today I'll post my whitepaper from that session on my web site.