Performance: How to move js to bottom of page and non blocking

[SynchroResearch]

Hi there,

I am a little obsessed with performance. The custom app I built (pre-sugar) had 1 second load times. I'm transitioning from that app to Sugar. So far with all my tweaking of server / client caching I've got Sugar to around 4 seconds to load most pages. I know it can do better though. I'm using yslow / fasterfox / google page speed etc.

I notice that they are using a yahoo js loader to minify and combine the needed javascript. But the problem is it is in the head, and blocking the page load.

Using W3 Total Cache has made my wordpress sites lightening fast, especially when I force it to combine all the javascript and put it just above /body. And make it non-blocking.

I'd like to apply that same strategy to sugar. The thing I can't seem to get is where are all the html template files are, so I can move around the location of the js files manually. And / or how can I adjust the loader to do this?

I'll make a separate post on exactly what modifications and tweaks I've made thus far to speed up sugar.

My details:
Linode VPS 512
Quad cord Xeon
512 mb ram
scsi array of disks
Debian Squeeze
Apache/2.2.16
PHP 5.3.3-7
Mysql 5.1.49 query caching etc etc.
.htaccess that caches everything except php / gzip and deflate / expires
apc and memcache

locally:
Firefox 3.6.13, yslow, fasterfox, google page speed

In my tests, most pages are ready in about 1-2 seconds, BUT then taking another 2-3 seconds to render the page (as far as I can tell it is partly because of the javascript issue, and because of the large number of dom elements)

I think getting this javascript loading issue could have a big impact on page transition loading time which would certainly benefit everyone.

Ideas?

Thank you!

David

[Weee]

I've checked this page with http://siteloadtest.com
I don't know what yslow tells you, but siteloadtest shows that the page is very bloated