Gentoo adheres to the following filesystem layout:
/bin: Boot-critical applications/etc: System administrator controlled configuration files/lib: Boot-critical libraries/opt: Non-standard layout applications/sbin: System administrator boot-critical applications/tmp: Temporary data/usr: General applications/usr/bin: Applications/usr/lib: Libraries/usr/local: Non-Portage applications. Ebuilds must not install here./usr/sbin: Non-system-critical system administrator applications/usr/share: Architecture independent application data and documentation/var: Program generated data/var/cache: Long term data which can be regenerated/var/lib: General application generated data/var/log: Log filesOn most Gentoo systems, though, some of those paths will be symlinks. For example,
/bin -> usr/bin/lib -> usr/lib/sbin -> usr/bin/usr/sbin -> bin