Hi Meher, ELF (Executable and Linking Format) is a binary format used by System V Release 4 Unix (and others)... http://www.lh.umu.se/~bjorn/linux/howto/ELF-HOWTO-1.html http://www.theparticle.com/cs/bc/os/elfpecoff.html http://www.arm.com/pdfs/DUI0101A_Elf.pdf I don't know what "arm-linux" is, so I cannot compare/contrast the two. HTH, --Eljay