whenever i boot red hat linux 7, it start off with 76000 KB of free 
physical memory.  i have a total of 128 MB of memory.  then i start an 
application like staroffice or realplayer or emacs or a game.  i know that 
when you start an application, that the operating system has to allocate 
memory for the program to be run.  my problem is this:  when i close the 
application, i type free, and it looks like linux has not deallocated the 
memory it used.  when i really loaded it, and then killed those apps, it 
said that i only had about 3000 KB of physical memory remaining while my 
swap file was hardly being used.  is there some kind of memory leak going 
on, is this the way linux works, or this is nothing to worry about?