Hi Peter!
Web developers can easily tackle those problems …
I’m afraid the word “easily” is wrong, Pablo. I’ve been doing mostly
web development for the last few years. I specifically mentioned those
things because they are hard to do in in web development, whereas in
desktop applications they are extremely easy to do or, in the case of
session time-outs, the problem doesn’t exist at all.
Of course, your point is right. I just tried to show that there are many solutions, known solutions and patterns we can use to tackle those problems down. That web is more dificult than desktop, no doubt about it.
The main problem is not on those usability issues, is on that in web we have to deal with lots of levels of abstraction to reach the application level, and in desktop we only have the operating system, maybe a virtual machine, and the application above. On web based we have to deal with a server (OS, VM, application server, web server, database server, etc), we have to deal with the client (web browsers, javascript, xml, json, html, css, etc), and with all in between (sockets, http, ajax calls, soap web services, security, …). Yeah! thats complex and dificult 
Just use HTML: http://en.wikipedia.org/wiki/Access_key
This doesn’t address keyboard shortcuts. Access keys are not keyboard
shortcuts. I’m sure there must be some way to do keyboard shortcuts in
a web application, because googling for “cloud9 keyboard shortcuts”
comes up with some relevant-looking results, but I really have no idea
how to achieve it.
Maybe I misunderstood the keyboard shortcuts term, I thought of a combination of keys to make focus on something on the GUI (a label or a form input).
It also doesn’t address at all my question about setting focus to the
appropriate control automatically. When I open a page, I want keyboard
focus set to a sensible place, probably the top-left entry control. If
I select an item from a drop-down list, I probably want focus to
remain on that drop-down list. If there’s an OK or Save button on the
page, then I should be able to click it without being forced to reach
for the mouse. Simple usability stuff that is programmed routinely
with almost no effort into a desktop app, and that is essential for me
personally, if I am to spend hours on end, day after day, using that
application. My experience of trying to get basic stuff like this
working properly in a web app is that it’s doable, but with a huge
amount of effort.
One way to maintain a session open is to send heartbeats using
AJAX …
That’s interesting. When I have a whole day free to investigate, I
might work out a way to implement this for my current project.
Hopefully that day won’t turn into a week, as such things have a
tendency of doing 
Yep, that was a good one when I learn the concept from a networking course in my university. It’s the same idea used for server monitoring: send small packets to know if something is still alive.
Anyway, this pretty well proves my point. The problem simply doesn’t
exist in desktop apps, but in developing a web app you have to devote
significant time to this problem instead of working on real
functionality. These are just a few examples of the many things that I
take for granted when programming desktop apps that suddenly become
very difficult for web apps …
I agree with you.
Cheers,
Pablo.
