These packages are either mandated by the core LaTeX team, or very widely used and strongly recommended in practice.

This package includes the following CTAN packages:

ae -- Virtual fonts for T1 encoded CMR-fonts

amscls -- AMS document classes for LaTeX

amsmath -- AMS mathematical facilities for LaTeX

atbegshi -- Execute stuff at \shipout time

atveryend -- Hooks at the very end of a document

auxhook -- Hooks for auxiliary files

babel -- Multilingual support for LaTeX, LuaLaTeX, XeLaTeX, and Plain TeX

babel-english -- Babel support for English

babelbib -- Multilingual bibliographies

bigintcalc -- Integer calculations on very large numbers

bitset -- Handle bit-vector datatype

bookmark -- A new bookmark (outline) organization for hyperref

carlisle -- David Carlisle's small packages

colortbl -- Add colour to LaTeX tables

epstopdf-pkg -- Call epstopdf "on the fly"

etexcmds -- Avoid name clashes with e-TeX commands

fancyhdr -- Extensive control of page headers and footers in LaTeX2e

firstaid -- First aid for external LaTeX files and packages that need updating

fix2col -- Fix miscellaneous two column mode features

geometry -- Flexible and complete interface to document dimensions

gettitlestring -- Clean up title references

graphics -- The LaTeX standard graphics bundle

graphics-cfg -- Sample configuration files for LaTeX color and graphics

grfext -- Manipulate the graphics package's list of extensions

hopatch -- Load patches for packages

hycolor -- Implements colour for packages hyperref and bookmark

hyperref -- Extensive support for hypertext in LaTeX

intcalc -- Expandable arithmetic operations with integers

kvdefinekeys -- Define keys for use in the kvsetkeys package

kvoptions -- Key value format for package options

kvsetkeys -- Key value parser with default handler support

l3backend -- LaTeX3 backend drivers

l3kernel -- LaTeX3 programming conventions

l3packages -- High-level LaTeX3 concepts

latex -- A TeX macro package that defines LaTeX

latex-bin -- LaTeX executables and man pages

latex-fonts -- A collection of fonts used in LaTeX distributions

latexconfig -- configuration files for LaTeX-related formats

letltxmacro -- Let assignment for LaTeX macros

ltxcmds -- Some LaTeX kernel commands for general use

ltxmisc -- Miscellaneous LaTeX packages, etc

mfnfss -- Packages to typeset oldgerman and pandora fonts in LaTeX

mptopdf -- mpost to PDF, native MetaPost graphics inclusion

natbib -- Flexible bibliography support

oberdiek -- A bundle of packages submitted by Heiko Oberdiek

pagesel -- Select pages of a document for output

pdfescape -- Implements pdfTeX's escape features using TeX or e-TeX

pslatex -- Use PostScript fonts by default

psnfss -- Font support for common PostScript fonts

pspicture -- PostScript picture support

refcount -- Counter operations with label references

rerunfilecheck -- Checksum based rerun checks on auxiliary files

stringenc -- Converting a string between different encodings

tools -- The LaTeX standard tools bundle

uniquecounter -- Provides unlimited unique counter

url -- Verbatim with URL-sensitive line breaks