Manchu and Mongolian script

The below functionality is available as the manchuxetex package on GitHub.

A minimal example as to demonstrate Khaled Hosny’s point of hacking Manchu/Mongolian into top-to-bottom, left-to-right:

% !TEX TS-program = xelatex
\documentclass{scrartcl}
\usepackage{fontspec}
\newfontfamily{\dcw}[]{DaicingWhite}%
\begin{document}
\noindent
Line above\\% to demonstrate that the lines are being stacked as normal
\rotatebox{-90}{%
\XeTeXupwardsmode1\\% successive lines will be stacked upwards instead of downwards
\begin{minipage}{4em}% this will be the vertical length of the Mongolian section
{\dcw% Font: Daicing White
1 ᠮᠠᠨᠵᡠ ᡤᡳᠰᡠᠨ\\% direct Unicode input of Manchu letters
2 ᠮᠠᠨᠵᡠ ᡤᡳᠰᡠᠨ
}% End font
\end{minipage}
\XeTeXupwardsmode0
}% End rotatebox

\noindent
Line underneath
\end{document}

This yields the following:

Daicing White’s letters are already rotated, therefore there is no need to use the Vertical=RotatedGlyphs font feature here.

in general you can use the Unicode numbers or the corresponding letters:

\documentclass{article}
\usepackage{fontspec}
\setmainfont{圈点满文印刷体}% the font name of manchu.ttf}
\begin{document}

abcdefghijklmnopqrst

\char055\char056\char057 

\end{document}

You hvae to use platex, lualatex or omega to write it in the correct direction from top to bottom.