For Mac Version, the system requirements have to be changed:
instead of the list given by now, just a
* Mac OS 10.6 (Snow Leopard) or higher
would do it - all other mentioned and/or needed requirements are requirements of Mac OS 10.6 already.
This implies also the end of PPC support on Mac OS because 10.6 runs only on Intel machines.
when changing this, bug https://bugs.freedesktop.org/show_bug.cgi?id=53904 should also taken in account.
And at last, the long text for Linux install hints is not necessary for a mac readme file. Wrong xsl filter variable?
btw I worked on this a few years ago and may help if asked, but I have no commit rights and even don't know if the file still is build based on XSLT filtering.
I see 18.104.22.168 PPC packages, so I'm not sure about this system requirement change.
As far as the 4.0 release notes on
"Deprecated Mac / PPC as a platform, raising our base-line to 10.6."
Whatever that means - imho something like "It may run using older Systems as well, but no guarantees. And it will stop to do so in near future."
So this should be reflected in systems requirements?
*** This bug has been marked as a duplicate of bug 81523 ***