| Library component | Content | Inclusion guidelines |
| ld (This library component is not itself a library. Instead, ld.so is an executable invoked by the ELF binary format loader to load the dynamically linked libraries into an application’s memory space.) | Dynamic linker. | Compulsory. Needed to use any shared libraries. Theoretically not necessary if using only a statically built root filesystem—although this is quite rare, unless you are only using BusyBox, for example. |
| libBrokenLocale | Fixup routines to get applications that have broken locale features to run. Overrides application defaults through preloading. (Need to use LD_PRELOAD.) | Rarely used. |
| libSegFault | Routines for catching segmentation faults and doing backtraces. | Rarely used. |
| libanl | Asynchronous name lookup routines. | Rarely used. |
| libbsd-compat | Dummy library for certain BSD programs that are compiled with -lbsd-compat. | Rarely used. |
| libc | Main C library routines | Compulsory. |
| libcrypt | Cryptography routines. | Required for most applications involved in authentication. |
| libdl | Routines for loading shared objects dynamically | Required for applications that use functions such as dlopen(). |
| libm | Math routines. | Required for math functions. |
| libmemusage | Routines for heap and stack memory profiling. | Rarely used. |
| libnsl | NIS network services library routines. | Rarely used. |
| libnss_compat | Name Switch Service (NSS) compatibility routines for NIS. | Loaded automatically by the glibc NSS |
| libnss_dns | NSS routines for DNS. | Loaded automatically by the glibc NSS |
| libnss_files | NSS routines for file lookups. | Loaded automatically by the glibc NSS |
| libnss_hesiod | NSS routines for Hesiod name service. | Loaded automatically by the glibc NSS |
| libnss_nis | NSS routines for NIS. | Loaded automatically by the glibc NSS |
| libnss_nisplus | NSS routines for NIS plus. | Loaded automatically by the glibc NSS |
| libpcprofile | Program counter profiling routines | Rarely used. |
| libpthread | POSIX 1003.1c threads routines for Linux. | Required for threads programming. |
| libresolv | Name resolver routines. | Required for name resolution. |
| librt | Asynchronous I/O routines. | Rarely used. |
| libthread_db | Thread debugging routines. | Loaded automatically by gdb when debugging threaded applications. Never actually linked to by any application. |
| libutil | Login routines, part of the user accounting database. | Required for terminal connection management. |