As I am living an almost mouse free life, automatically setting the input focus at the window (or input field) that I am currently looking on, would be a very nice comfort feature.
Last time I researched this, I could not find a solution, that works on Linux and also has widescreen support.
I am mostly mouse-free too, so I feel inclined to answer.
For many pieces of software it's possible to use it with a keyboard-only. This is neccessary for accessibility, but it's also just what the good old hotkeys do.
Doesn't work for everything but it already gets you very far.
On top of that, there is some software that is made to cater specifically to keyboard-only use. Many tiling window manager work well with just a keyboard ( I personally am partial to i3[0]) and even for webbrowsers there are extensions like tridactyl[1] that make it easier to use without a mouse. That doesn't work for everything. It's possible to do 3d work without a mouse - but I find it easier to have access to a mouse. Specifically a trackpad.
This can of course be turned on it's head, and you can use something like dasher[2] to do your typing and - to get this back on topic - dasher can be used together with eye tracking to live a "keyboard free life"
Last time I researched this, I could not find a solution, that works on Linux and also has widescreen support.
Will definitely check out this python package.