[Sugar-devel] webkit, hulahop; developing apps using browser engine DOM for widgets

[Luke Kenneth Casson Leighton]

> Two things to consider when looking at this...
>
>  - Startup, memory use and general responsiveness on XO hardware and general
> netbook hw. The current Browse.xo compares _very_ favourably with Firefox
> and Opera on XO-1 hardware.

* webkit is known for / designer for very good performance and low
memory usage, and is used in nokia S60 phones, the iphone, the latest
palm phone (as the basis for WebOS), google android's web browser -
you name it, webkit's been there and done that.  [it should tell you
something that the world's top major smart-phone manufacturers _don't_
use firefox, or they pay for opera]

* squirrelfish, the JIT javascript accelerator, has a 32-bit x86 port
as well as a 32-bit ARM port.  even without this (on a debian amd64
system), a simple empirical use of webkit from august 2008 absolutely
smoked firefox 3.0 by a good 2-3 times speed increase, for the large
"web 2.0" pyjamas (javascript-only) test apps i was running.

* progress is being made to port the use of google's v8 JIT javascript
compiler engine into webkit.  as is google's habit they throw
resources at projects, in this case the google chrome project; the
engineers added V8 to _their_ version of webkit, and merging back is
taking quite some time.


>  - Behaviour in non-standard-dpi screens the require scaling. The XO screens
> have 200dpi physical pixels, with a 'perceived dpi' of ~133px.

 yes - with the funny 4-block thing.  great idea, that.

> Currently
> gecko suffers a lot due to how images end up being scaled -- see the
> discussion in
> http://wiki.laptop.org/go/HTML_canvas_performance -- and
> this is bound to affect other hardware as well.

 hmm - outside of my experience.

 ... ah.  but.  wait.  ziproxy.  have you heard of it?  it's a
(forwarding-only) web proxy.  what it does is process images and
leaves other HTTP traffic alone.  basically it compresses them.

 if there's a standard algorithm that's been developed already, and is
recommended for use in processing images to a more "readable" form, in
some way, then it might be worthwhile throwing that into ziproxy.

l.