Announcement for Mathematica for Macintosh customers who have not yet installed Mathematica 10 and have upgraded to, or will upgrade to, MacOS 10.9.5 (or higher).

A revised download is now in User Portals ( http://user.wolfram.com ). It handles installation and configuration in a manner acceptable to Apple's new code signing convention.

NOTE: under the hood, this is the same 10.0.1.0 that was available before. There are no new features or fixes.

Instead of the Drag-and-Drop installation method, this uses a more typical installer to put files in place. There is an accompanying Support FAQ article "How do I install Mathematica 10 on Mac OS X?" at http://support.wolfram.com/kb/16122 .

Fyi, this installer takes longer to copy files from the DMG into /Applications/Mathematica.app - 10-20 minutes.

An alternative, if you have already downloaded the first 10.0 installer, is to use one of the workarounds given in
http://community.wolfram.com/groups/-/m/t/348295 .
(There are three workarounds - two in the top post and one lower down.)