I've always assumed that youtube videos are embedded with the iframe, so you can't customize the player, but I've just learned that there's a custom video player for embedding youtube videos on your site, which removes youtube logo, titles, ads, etc.

How did they do that? Is there an article/tutorial that can help me to figure out how to do something like this?

Is there an open source project that does something similar which I could learn from?

To make the question more specific - can you help me to figure out a piece of code that does some simple part of this, such as removing a youtube logo from the embedded video, or playing/pausing the video using my own custom button?