What's different about Google Apps?
Four important things. Here's the fourth:
Google just released it in April to the public,
and it is still classified as a 'beta release'
That's good news and bad news:
The good news is that it's free - totally free for now, and,
according to public Google promises, always free to the small-volume user.
They will, sooner or later, have a 'commercial' program, where high-volume users
and users of special features will pay more.
Google released a preliminary price sheet
here.
The bad news is that it still has a few rough spots, limitations, and holes.
Among the most notable are:
(a) The volume limits: only a few seconds per process,
only so-many processes per day, only so-much disk space, etc.
The real figures are
here.
(b) The storage restriction: you can't write to a regular file, only to
Google's "bigtable" storage mechanism, using their almost-SQL interface;
(c) No 'secure' communications - i.e. no HTTPS communication -
so any data you send to the Google App Engine is sent in the clear
over the wild Internet for anyone to see.
Update, October 2008: Google is now supporting HTTPS.
The announcement is
here and documentation is
here .
(d) No scheduled processes, e.g. daily 'batch jobs';
everything is triggered by a web request.
There are some work-arounds to handle this -
the most obvious is to set up a process on a machine of your own that
sends a request to the Google App to "do its duty."
And it seems pretty likely that the Google Apps developers will find a way
to enhance Google App Engine to support this important requirement by itself.
