Is there a common set of packages that is available in every distribution?

Question

Or at least in most distributions...

Answer 1

In theory, the only packages that are guaranteed to be present are the ones which are part of the latex distribution itself, and the ones in /macros/latex/required. To quote:

These are packages that the LaTeX team have declared are ‘required’ of any LaTeX distribution—in the sense that any package writer is entitled to assume the presence of these packages in support of her package.

You get amslatex, babel, slovak, cyrillic, grfguide, graphics, graphicx, trig, keyval, epsfig, color, psnfss, afterpage, array, bm, calc, dcolumn, delarray, enumerate, fileerr, fontsmpl, ftnright, hhline, indentfirst, layout, longtable, multicol, rawfonts, showkeys, somedefs, tabularx, theorem, trace, varioref, verbatim, xr, xspace.

In practice, if it's on CTAN, it's probably in your distribution.

Answer 2

The two main TeX distributions are TeX Live and MiKTeX. Of the two, TeX Live defaults to installing 'everything' while MiKTeX starts with a small, basic set of packages. So the 'core' you can assume is likely to be available is defined more or less by what MiKTeX installs as 'basic' packages. Of course, if you mean Linux distros then life is very different.

Answer 3

Modern distributions are extremely large (often several gigabytes), and while most of the space is taken by fonts, these distributions also include a wealth of packages.

In fact, most packages that are distributed via the CTAN directory are included in all modern distributions – at the moment, that’s 2300 packages in contrib alone (i.e. packages that are not part of the LaTeX core).

Notice that not all of them are installed by default, depending on your distribution. For example, MikTeX prefers to install packages on demand, i.e. as soon as they get used. TeX Live, on the other hand, installs most of them (all of them?) by default.

There’s also a slight lag between the time that packages are released on CTAN and the time they are included into the various distributions, so not all packages on CTAN are part of all distributions yet.

Answer 4

There is, I am afraid, nothing like Python's standard library, which comes with a long list of uniformly documented modules.

Add to that that there's plain TeX, LaTeX and ConTeXt, the whole situation is quite sorry indeed.

Good question, and perhaps in a couple of years they'll be a more encouraging answer.