Virtual Memory

If you don't have enough virtual memory to run all the applications you want to run, then pull down the colorful apple menu (upper left hand corner), select the "Control Panel" submenu, and select from it the entry called "Memory". Reset the virtual memory to a large number, say, 100MB, and then restart the machine (under the Special menu) so it will take effect.

It is also a good idea to tell the Mathematica kernel and front end to start out with a fair bit of memory. In the Mathematica folder, click (just once) on the Mathematica icon, pull down the File menu, select the "Get Info" entry, and in the window that pops up, set the preferred memory size to 10000K. Do the same for the Mathematica Kernel, but set its preferred memory size to 15000K.