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LaTeX Development Code

The base files of LaTeX are managed and developed in a number of GitHub repositories. The most important ones are:

There are various other repositories, e.g., babel, hyperref, l3build, luaotfload to mention a few, all of which are managed by the LaTeX Project Team. In addition several members have their own repositories from which they distribute further LaTeX packages that are in general use.


The LaTeX code is installed and tested using l3build configuration files. l3build is a cross-platform Lua program for automating the building and testing process of (primarily) LaTeX package files, and it is also developed by the LaTeX team.

Obtaining it

Most of the LaTeX code is directly available and automatically kept up-to-date through all major TeX distributions so you just get it automatically (or manually) through the update mechanism of your installation.

There is also the possibility to run the version for the next release using the so-called -dev formats which are curated prereleases (that we believe are suitable for use and testing)

However, if you wish to test the unreleased development code on GitHub, you may clone one of the repository using for example

git clone

To locally install packages from the development repository, use l3build as follows:

cd l3kernel
l3build install

In some cases (for example for l3kernel because this is the L3 programming layer so is loaded into the format) you may need to update the formats afterwards, but in most cases the local install is sufficient.

Important note: Files installed via l3build install are stored in your local texmf tree, which is searched first when the TeX program looks for files. Thus later updates that you receive through the normal distribution mechanism will never get used, unless you delete the local files or set up you system so that you can switch trees as needed!

You may alternatively wish to ‘fork’ the repository on GitHub and clone your fork if you wish to make changes to the code and contribute them back via Pull Requests but please read the LaTeX contributing guidelines and L3 contributing guidelines first.

Bug reports

You may raise any issues concerning the LaTeX format code or the core packages in the LaTeX2e Issue Tracker. Please read the explanation on how and when to raise a bug report first. In order to be able to do a decent job, we need your help in providing the right kind of information when submitting a bug report — thanks in advance.

Bugs directly related to the L3 programming layer or bugs about L3 code that is not integrated in the LaTeX format are better raised in the L3 Issue Tracker.

Issues opened are usually intended to report issues relating to the code, such as documentation clarifications, missed functionality, or bugs. Please do not use the issue trackers to request help with your documents. Other channels such as stackexchange are much better suited for obtaining help.

Discussing it

The concepts developed by the LaTeX development code, as well as their implementation, are under discussion on the mailing list ‘LATEX-L’. You can join this list, which is intended solely for discussing ideas and concepts for future versions of LaTeX, by sending mail to listserv@URZ.UNI-HEIDELBERG.DE containing the line


Listserv web interface

There exists a web interface to the list that can be used to read through the posts sorted by topic and month. By default this is available to the general public in a read-only mode. If you would like to post using this interface, you have to be subscribed to the list and you need to log on (which is an option on the page).

Archived posts

This list is archived and, after subscription, you can retrieve older posts to it by sending mail to the above address, containing a command such as:


where yy=Year and mm=Month, e.g.


for all messages sent in March 2017.