Run Mac OS X Server 10.6 in emulation or give up; it's otherwise not possible.
MichaelLax, greetings: Not quite the case. I do recognize that all OS have a lifespan and newer ones generally incorporate improvements in contrast to prior versions. It depends upon what one views as improvements. There are two types, ease of use and the introduction of a new feature.
In the case of the former, in Tiger if one had several windows open, in order to close one that was behind the one that was displayed, the user would not be able to click on the red button to eliminate it, but rather click on it to bring it to the front and then click on the the red button. In Leopard, you could eliminate any window by clicking on the red button regardless of its position in relation to other windows, so long as the button was visible. In short, a one vs two click process.
It would seem like a very small an insignificant detail but magnify it by the number of times the user does it and in concert with similar ease of use procedures can make the difference between an OS that is easy to use or not.
Also with the introduction of Leopard was Time Machine which was a truly worthy new feature which justified the new OS on that basis alone.
In regards with the Lion's I have picked up several reversals in the ease of use category and I have registered my dissatisfaction with Apple support. Some of the new features such as Launch Pad and Mission control among others I find to be of dubious value.
Am I against new OSs. Not at all. I have Lion as the principle OS in the late 2011 MBP with Snow Leopard in a partition. In the 2010 MBP I have Snow Leopard as the principle OS with Mt. lion in a partition. However I do look forward to an OS, or a Mt. Lion upgrade, that will eliminate the flaws that I have found.
All companies like to make one believe that the latest product is the best ever and makes the prior versions obsolete. I say that obsolescence if more often a perception rather than a reality. I find that a five year old Mercedes can deliver you in comfort to your destination as well as a new one, or at least close enough.