XEXMenu is a file manager / FTP server / dashboard for the Xbox 360, it can launch for XEX Homebrew, Games, Apps and Emulators from a USB drive, Internal hard drive or even a DVD.
XEXMenu has two different versions, which can be incredibly useful for different situations.
The ISO version of XEX Menu is useful for people with new Jtag or RGH Xbox 360 consoles. You can burn the ISO of XEX Menu to a CD or DVD and place it in the Xbox 360. You can then load XEX Menu directly from the dashboard, giving you FTP access to the Jtag or RGH hacked Xbox 360. In addition you also have access to install content from a FAT32 formatted USB hard drive.
XEX Menu allows you to copy content to a USB hard drive using a computer and then load that content on the Xbox 360, this is an advantage for people who dont wish to use special tools to gain access to the Xbox 360's unique FATX file system.
The ISO of XEX Menu is also handy in helping newbies to the Xbox Scene in launching the installers for Dashlaunch after updating your console, allowing you to quickly restore the Xbox 360's ability to boot in to a replacement dashboard, such as FreeStyle Dashboard.
The Live version of XEX Menu can be injected in to an Xbox 360 formatted usb stick using tools such as Party Buffalo Drive Explorer or even copied across from a USB hard drive to the internal hard drive when used with the ISO version of XEX Menu, allowing XEX Menu to be used without a disc in the Xbox 360 console.