On the subject of 64-bit improvement, there was an argument to wait until
PHP6 so that extension maintainers had to deal with one extension
conversion, but a more broad one (because there will be other things
changing). I actually think it is not such a great idea, because when
dealing with multiple things to update, it is far easier to break something
or mess it up.
I want to point out, that although the adoption of PHP picked up the pace,
new versions are not adopted that fast. Many leaped over 5.4 to 5.5 because
5.4 does not have a working opcode cache and that is a major no go for
almost everyone.
Nethertheless, when PHP 6 is released, many will leap from 5.3 or 5.5
straight to it. 5.6 can be a kind of grace period to port and test the
extensions, so the majority of them is updated when PHP 6 comes. This will
also spread the workload and give a chance for everyone to catch up with
the 64 bit support. As part of this effort, there has to be an
informational campaign to inform people that extension developers have to
convert them. This has to be shown clearly and loudly (php.net front page
pinned announcement with linkage to the explanation of what the heck is
going on, also we should announce it all on any other channels that are out
there).
On the case of concerns of Yahoo and alike - it does not really matter,
because they have to do this work anyway - sooner or later, but the amount
of the required work does not change. Actually, if you cram too many
changes in a single release (PHP 6), you end up with even bigger workload,
because now you have to implement 64 bit support and other PHP 6
compatibility things - you end up in a state when for extension to work,
you have to do all the changes at once without the ability to separately
test if you 64 porting was done correctly. You end up with multiple changes
in one place and have to debug them all simultaneously.
The fact, that some companies still stick with 5.3 and don't update their
own code base does not concern the PHP developer team. It does not matter
if you do 64 bit support in 5.6 or 6.0 - Yahoo has it's own schedule and
they might migrate from 5.3 to 5.5 (well, because 5.4 has issues with
opcode cache - it's understandable to skip it over) and that plan may be
already in motion. So it will not matter for them if 5.6 has 64 bit support
or not. They might just wait for the PHP 6 after 5.5 (and it kind'a makes
sense).
So, I say you go with the 64 bit improvements for 5.6, set all the things
in motion, do the porting docs and make a hell lot of noise about this. I'm
willing to help with the information campaign, because this lack of proper
64 bit support has gave me a few "WTF?!" situations when I had to figure
out why things do not work and realize it's due to the 64 vs 32 bit issues.
Arvids.