I am a begginer in unix and would like to know which freebsd version is considered the most stable and reliable. So far i have the freebsd 4.2 powerpack, but am wondering if the downloaded version of freebsd 5.1, 5.2 will allow me to install freebsd 4.2 third-party software form the 4.2 powerpack edition i have puchased 3 years ago.