[Tex/LaTex] What are the ways to position things absolutely on the page

Question

I know that there is tikz, but also eso-pic and textpos. I'd like to see a list of possible ways (not necessarily packages) for absolute positioning of things (which I believe amounts to "boxes") on the page, together with their advantages and disadvantages (for instance: tikz's current page node is very easy to use, but usually requires two LaTeX runs, and overhead from loading tikz if you don't need it for any other things is considerable).

Both LaTeX and ConTeXt solutions are welcome

Answer 1

A LaTeX kernel change from Dec 2018 caused different behavior in \smash, which affected this answer. Thanks to Ulrike for diagnosing the issue for me and providing the best fix at Change in everypage package behavior (which hasn't been revised since 2007)

This method allows you to position at any (x,y) location (relative to upper left corner of paper) on the page, and can be issued regardless of where the current location is. The only requirement is that you know what the top and left margins are, which are incorporated in \atxy. It uses the everypage package.

If you prefer the origin at a different location, for example, relative to the margins, that is a trivial change.

\documentclass{article}
\usepackage{everypage}
\usepackage{xcolor}
\usepackage{lipsum}
% THESE ARE LaTeX DEFAULTS; CAN CHANGE IF NEEDED.
\def\PageTopMargin{1in}
\def\PageLeftMargin{1in}

% ORIGINAL DEFINITION
\newcommand\atxy[3]{%
 \AddThispageHook{\hbox{\smash{\hspace*{\dimexpr-\PageLeftMargin-\hoffset+#1\relax}%
  \raisebox{\dimexpr\PageTopMargin+\voffset-#2\relax}{\textcolor{red}{#3}}}}}}
% VERIFIED THAT SETTING \hoffset AND \voffset DO NOT BREAK SOLUTION.
%\hoffset=0.4in
%\voffset=0.2in
\begin{document}
\atxy{6in}{4in}{(6,4)}
\lipsum[1]
\atxy{0in}{1in}{(0,1)}
\atxy{5in}{6in}{\textbullet(5,6)}
\atxy{5in}{6.2in}{\makebox[0pt]{centered at (5,6.2)}}
\end{document}