I have used Skype video chat between Mac-Mac computers, and between Windows-Windows computers, and each can see the other's video.
However, when I used a Mac with a Windows, the Mac can see the Windows video plus its own video, but the Windows computer cannot receive the video from the Mac.
For the Mac, I used iSight as well as the Logitech Quickcam Notebook pro which works very well on the Mac. Just that, both iSight and the Logitech cannot be received in the Window computer.
I would appreciate receiving suggestions from people who have used Mac-Windows for video chats. Thanks in advance.