In the Arduino package are local files of the reference.
On the page Libraries.html
the standard library Firmata
But when I click to its link, I just came to a dead page.
Please add the Firmata page (as file) to the Arduino package.
If possible it would be good to use a tool which creates links to the website if a linked file/page isn't in the package.
The reference I opened by the Arduino IDE.
I thought this would be the Arduino website and was confused that some things didn't work.
Later I found out, that it's only a local copy of some pages.
So http links to the other pages (without local copy) would be very useful.
Just as an improvement idea