What is this, is it something we actually have now, and where can I
learn enough about it to be able to document it if need be? At a
minimum, MDC should mention it somewhere as appropriate, I expect.
Eric Shepherd
Developer Documentation Lead
Mozilla Corporation
The fastload is used to parse xul and scripts and then save the
post-parsed data in a binary form to disk, thus improving load time
later. We've had it for a long while, usually it's referred to as the
'xul cache'. There should already be documentation about disabling it
(the nglayout.debug.disable_xul_cache preference).
I don't know if the performance improvement made in the page you
referenced was done. This wouldn't need to be documented on mdc though
as its only underlying architectural work.