Can I run plain TeX on Overleaf?
Yes—you can configure your project to be compiled using plain TeX by following the setup procedure described below.
- In the Overleaf editor, click on the Menu button and set the Compiler option to
LaTeX
—selectLaTeX
from the dropdown list as shown in the following video clip: - Add a blank file to your project, and save it as
latexmkrc
—it should not have any file extension (you may not need to add this if your project already has alatexmkrc
file). - Add the following line to your
latexmkrc
file:
$latex = 'tex %O %S';
What does this file latexmkrc
actually do?
Without going into detail, Overleaf's servers use a program called latexmk
to run and control TeX/LaTeX-based typesetting. The latexmk
program allows Overleaf users to influence typesetting of their projects by adding a configuration file called latexmkrc
. Readers wishing to further explore this can read about the latexmkrc
configuration file on the latexmk
web site.
Examples
The latexmk
program is written in the Perl programming language which uses the hash character (#) as the comment character (much like TeX/LaTeX typically use the % character). If you wish to experiment with plain TeX using different TeX engines you can create a latexmkrc
file and copy/paste the following text into it:
# $latex = 'tex %O %S'; # to use Knuth's original TeX engine # $latex = 'pdftex %O %S'; # to use the pdfTeX engine # $latex = 'luatex %O %S'; # to use the LuaTeX engine # $latex = 'xetex %O %S'; # to use the XeTeX engine
To use a particular TeX engine, uncomment the line (delete the initial '#' character) for the TeX engine you want to use. For example, to run XeTeX you uncomment the last line so that your latexmkrc
file looks like the following—note that the last line does not start with a '#' character, thus it gets executed/run to typeset your plain TeX document using XeTeX:
# $latex = 'tex %O %S'; # to use Knuth's original TeX engine # $latex = 'pdftex %O %S'; # to use the pdfTeX engine # $latex = 'luatex %O %S'; # to use the LuaTeX engine $latex = 'xetex %O %S'; # to use the XeTeX engine
The following short video shows the above latexmkrc
file being selectively edited to run each TeX engine in turn—starting with XeTeX. The plain TeX source code used in this example was borrowed from an article by D. R. Wilkins.
Further reading
We have two related help items which may be of interest to any reader wishing to better understand Overleaf's use of latexmk
and latexmkrc
: