We must buy upgrade every year?

[SungSuK]

I bought upgrade from 8 to 9 at 23h jun 2014.
I bought upgrade from 7 to 8 at 1st Mar 2013 too.
Today, I tried to install El Capitan.
My parallels 9 does NOT work El Capitan.

2013,2014,2015....
We must buy upgrade every year?
Parallels does NOT work new OS (It release every year).
How about VMWare?

 

[Sylvester@Parallels]

Hi,
It is not mandatory to upgrade your Parallels Desktop every year.
However, upgrade is necessary in order to meet the system requirements of Guest OS/Host OS environment.
Parallels is a software company that focuses its resources on creating virtualization software to support both the Mac and Windows communities. Since Apple releases new operating systems every year, we have to keep our software up-to-date to be compatible with every new OS X getting released annually. This development is very resource-consuming and comes with cost, and unlike Apple (which sells a lot of hardware products and able to afford free-of-charge OS upgrade) it is not feasible for Parallels to offer no charge upgrades to the new versions of Parallels Desktop.

The current Parallels Desktop version is 11, but you did not need the help of Parallels Desktop version 10 so far, as Parallels Desktop 9 was taking care of all the system requirements until you decided to upgrade to OS X El Capitan . So upgrading Parallels Desktop on a consistent basis is not needed until there is a major change in the Guest/Host operating system environment.