as stated there is no operating system called "linux 5"
however as a guess there ARE THESE
RHEL5.7 ( and 5.6,5.5,... 5.0) NOT FREE!!!
CentOS 5.7 ( and 5.6 ) - free
Scientific linux 5.7
if red hat 5.? you MUST buy a license
if cent then see the wiki
but be warned on RHEL or one of the free rebuilds
Audio / video software can VERY VERY VERY easily kill the install
there are A LOT of incompatible rpms