Microsoft Internet Explorer per Mac non è disponibile per le ultime versioni di OS X (oltre OS X 10.4) poiché è stato effettivamente sostituito da Safari nel 2003. Come la pagina di Wikipedia per Internet Explorer per Mac spiega:
As a result of the five-year agreement between Apple and Microsoft in
1997, it was the default browser on Mac OS and Mac OS X from 1998
until it was replaced by Apple's own Safari web browser in 2003.
On June 13, 2003, Microsoft announced that it was ceasing further
development of Internet Explorer for Mac and the final update was
released on July 11, 2003. The browser was not included in the default
installation of Mac OS X v10.4 "Tiger" which was released on April 29,
2005. Microsoft discontinued support for the product on December 31, 2005 and removed the application from their Macintosh downloads site
on January 31, 2006. Microsoft recommends "that users migrate to more
recent web browsing technologies such as Apple's Safari."
La soluzione migliore è scaricare la versione Windows di IE ed eseguirla una macchina virtuale (utilizzando qualcosa come VMware Fusion o Virtual Box ).
In alternativa, l'articolo OSXDaily su Internet Explorer per Mac in modo semplice: Esegui IE 7, IE8, & IE9 gratuito in una macchina virtuale descrive un modo per farlo (non l'ho usato da solo, ma questo sembra aggirare il periodo di prova di Windows di 30 giorni utilizzando snapshot e possibilmente per rispettare l'EULA che dovresti acquistare una licenza Windows e utilizzarla in una VM con una versione scaricata di IE, come sopra, invece):
We’re going to walk you through how to install Internet Explorer 7, 8,
or 9 in a virtual machine running Windows, directly in Mac OS X – for
free. This is achieved by using the freely available VirtualBox
software from Oracle, and combining that with free Internet Explorer
testing virtual machines from Microsoft, the trick is converting these
free IE vm’s so that they work flawlessly under OS X (or Linux,
technically), and that is all handled automatically with this method.