From FlexBuilder to CS3 or FlashDevelop?

I have inherited a Flash project that (I THINK) was started in FlexBuilder, but I dont have FlexBuilder. I have CS3 and FlashDevelop, is it possible for me to continue this project using the tools that I have?

There are a bunch of wierd files like “.project” and “.actionScriptProperties”, and obviously no .FLA file. How can I get up and running using either CS3 or FlashDevelop?

Or can I?

Thanks.