I boot many x86 OSes on my test machine at home. These include Windows, BeOS, multiple distros of Linux, and QNX. I have found GAG (http://gag.sourceforge.net/) to be the easiest to use. being graphical makes it even easier.
Generally for triple booting we need a boot loader with chain loading feature. When BIOS selects hard disk as boot device, booting data will be loaded from MBR. In chain loading, the boot loader writes its own program into Master Boot Record in hard disk. This program loads a OS boot sector chosen by user from several operating systems in different addresses.
I boot many x86 OSes on my test machine at home. These include Windows, BeOS, multiple distros of Linux, and QNX. I have found GAG (http://gag.sourceforge.net/) to be the easiest to use. being graphical makes it even easier.