[dcabrejas]

It means the start of a variable name, as simple as that, it isn't anything significant. Maybe it was made to make parsing the language easier at the time, who cares?

You can get used to that in 10 min and move on with your life, it is not a reason to not pick up the language, it's bike shedding.

[jhgb]

There was a number of other reasons why I didn't end up using PHP, so it was a bit like death by a thousand cuts. It was not the reason for me, just a small showcase of the weirdness for a newcomer.