# What can *I* do to help the LaTeX3 Project

First, I appreciate this may not be the right place for this question, so absolutely no offence if it gets closed.

I'm very much an end-user, rather than a programmer, of LaTeX, and I watch with awe and wonder, and often complete bewilderment, as, bit by bit, more LaTeX3 questions or answers flow by here in TeX.SX. But always with the thoughts "I wish I could do that" and "I'd love to help, but...".

So:

1. In what ways could a strict end-user or almost-noob help the LaTeX3 project? (And yes, "keep out the way" is an absolutely understandable answer.)

2. What's an appropriate reading list for someone at my level of skill who doesn't necessarily want to delve into the bowels?

3. What else do I need to know?

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Easy tasks: 1. You can use LaTeX3 and therefore test it; 2. You can read the documentation and report typos/mistakes. –  Andrey Vihrov Feb 26 '12 at 10:43
I think this question should be CW. –  Thorsten Donig Feb 26 '12 at 11:02
@AndreyVihrov: It's not obvious how to test LaTeX3. Does one simply use the new LaTeX3 related packages? If so, is there a list of these packages available? Is there a specific command to use in a terminal? etc. –  qubyte Feb 26 '12 at 12:24
@MarkS.Everitt: Then consider that a rhetorical answer ;-) –  Andrey Vihrov Feb 26 '12 at 14:22
@StefanKottwitz I beg to disagree with Thorsten Donig and you that this should be a community wiki. Perhaps it is not a question that easily fits the site (though I think it is important and helpful), but it is geared towards what the L3 project thinks is helping the project. That doesn't mean mean there should be different answers or discussions, but I definitely wouldn't like to see an answer of mine be "community improved" on this subject. –  Frank Mittelbach Apr 27 '12 at 18:29

As I have tried to explain in answer to the question "LaTeX3 versus pure lua" my vision of LaTeX3 is really a system with multiple layers that provide interfaces for different kind of roles. These layers are

• the underlying engine (some TeX variant)
• the programming layer (the core language, i.e., expl3)
• the typesetting foundation layer (providing higher-level concepts for typesetting)
• the typesetting element layer (templates for all type of document elements)
• the designer interface foundation layer
• the class designer layer (where instances of document elements with specific settings are defined)
• document representation layer (that provides the input syntax, i.e., how the author uses elements)

If you look at it from the perspective of user roles then there are at least three or four roles that you can clearly distinguish:

• The Programmer (template and functionality provider)
• The Document Type Designer (defines which elements are available; abstract syntax and semantics)
• The Designer (typography and layout)
• The Author (content)

As a consequence the LaTeX3 Project needs different kind of help depending on what layer or role we are looking at.

The "Author" is using, say, list structures by specifying something like \begin{itemize} \item in his documents. Or perhaps by writing <ul> ...</ul> or whatever the UI representation offers to him.

The "Document Type Designer" defines what kind of abstract document elements are available, and what attributes or arguments those elements provide at the author level. E.g., he may specify that a certain class of documents provides the display lists "enumerate", "itemize" and "description".

The "Programmer" on the other hand implements templates (that offer customizations) for such document elements, e.g., for display lists. What kind of customization possibilities should be provided by the "Programmer" is the domain of the "Document Designer", he drives what kind of flexibility he needs for the design. In most cases the "Document Designer" should be able to simply draw templates (already written) from a template library and only focus on the design, i.e., instantiating the templates with values so that the desired layout for "itemize" lists, etc. is created.

In real life a single person may end up playing more than one role, but it is important to recognise that all of them come with different requirements with respect to interfaces and functionality.

## Programming Layer

The programm layer consists of a core language layer (called expl3 (EXP erimental L aTeX 3) for historical reasons and now we got stuck with it :-)) and two more components: the "Typesetting foundation layer" that we are currently working on and the "Typesetting Element Layer" that is going to provide customizable objects for the design layer. expl3 is in many parts already fairly complete and usable the other two are under construction.

Help is needed for this layer in

• helping by extending and completing the regression test suite for expl3
• helping with providing good or better documentation
• possibly helping in coding additional core functionality but that requires in contrast to the first two points a good amount of commitment and experience with core language as otherwise the danger is too high the the final results end up being inconsistent

Once we are a bit further with the "Typesetting foundation layer" we would need help in

• providing higher-level functionality, perhaps rewriting existing packages/code for elements making use of extended possibilities

Two steps down the road (once the "Designer Layer" is closer to being finalized) we would need help with

• developing templates for all kind of elements

In summary for this part we need help from people interested in programming in TeX and expl3 and/or interested in providing documentation (but for this a thorough understanding of the programming concepts is necessary too).

## Design Layer

The intention of the design layer is to provide interfaces that allow specifying layout and typography styles in a declarative way. On the implementation side there are a number of prototype implementations (most notably xtemplate and the recent reimplementation of the ldb). Those need to get unified into a common model which requires some more experimentation and proably also some further thoughts.

But the real importance of this layer is not the implementation of its interfaces but the conceptual view of it: provisioning a rich declarative method (or methods) to describe design and layout. I.e., enabling a designer to think not in programs but in visual representations and relationships.

So here is the big area where people can help that do not feel they want or can program TeX's bowls. What would be extremely helpful (and in fact not just for LaTeX3) would be

• collecting and classifying a huge set of layouts and designs
• designs for individual document elements (such as headings, TOCs, etc)
• document designs that include relationships between document elements
• thinking about declarative good ways to specify such designs
• what needs to be specified
• to what extend and with what flexibility

I believe that this is a huge task (but rewarding in itself) and already the first part of collecting existing design specifications will be a major undertaking and will need coordination and probably a lot of work. But it will be a huge asset to test any implementation and interfaces for this layer later on.

## Document Interface Layer

If we get the separation done correctly, then this layer should effectively offer nothing more than a front end for parsing the document syntax and transforming it into an internal standarized form. This means that on this layer one should not see any (or not much) coding or computation.

It is envisioned that alternative document syntax models can be provided. At the moment we have a draft solution, the xparse package which offers a document syntax in the style of LaTeX2e, that is with *-forms, optional arguments in brackets, etc. but with a few more bells and whistles such as a more generalized concept of default values, support for addition delimiters for arguments and so on. It is fairly conventional though. In addition when it was written the clear separation of layers wasn't well-defined and so the package also contains components for for conditional programming that I don't any longer think should be there.

Bottom line on what is needed for this layer is to

• think about good syntax for providing document content from "the author" perspective
• think about good syntax for providing document content from an "application to typesetting" perspective, i.e., the syntax and structure for automated typesetting where the content is prepared by a system/application rather than by a human

The two might want need structures (in fact most likely need, as automation works much better with structures that do no have a lot of alternative possibilities ad shortcuts etc) and even if just looking at the human author a lot of open questions need answering. And these answers may or may not be to painfully stick with existing LaTeX2e conventions in all cases (or perhaps with any?).

None of this requires coding or expl3 experience. What it requires is familarity with existing input concepts, a feel for where the pain points are currently and the willingness to think and discuss how alternatives and extensions could look like.

## In Summary

Basically help is possible on any level and it doesn't need to involve programming. Thoughts are sprincled thoughout the article above, but here are a few more high-lights:

• help with developening/improving the core programming layer by
• joining the effort to improve the test suite
• help improving the existing (or not existing) documentation
• joining the effort to produce core or auxilary code modules
• help on the design layer by
• collecting and classifying design tasks (what is needed ...)
• thinking and suggesting ways to describe layout requirements in a declarative manner
• help on shaping the document interface layer

The concepts, as well as their implementation, are under discussion on the 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

Once you are subscribed you can post by email sending the post to LATEX-L@LISTSERV.UNI-HEIDELBERG.DE.

Gmane hosts a web interface, including archives, of the LATEX-L list: http://news.gmane.org/group/gmane.comp.tex.latex.latex3. If you are subscribed to LATEX-L as outlined above you can use this web interface to participate in discussions on the list, otherwise you can only read the entries made by others.

The list has only a fairly low traffic right now as actual implementation and development tasks are typically discussed directly between the few active implementors. But this might change if further people join.

## And something else ...

The people on the LaTeX3 team are also committed to keep LaTeX2e stable and even while there isn't that much to do these days there is the need to resolve bug reports (if they concern the 2e core), provide new distributions once in a while, etc. All this is work that takes effort or remains undone or incomplete. Thus here too, it helps the LaTeX3 efforts if we get help to free up resources.

Most notably: we recently restarted an effort to get Babel for LaTeX2e back on track and there any help is welcome. If you want to join this effort get in touch with @JavierBezos or myself or contact us on LATEX-L.

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Frank, in case you needed encouragement, please bear this in mind: I'm very much down at the blunt end of (La)TeX -- almost a total end-user. Following an earlier recommendation in this Q&A, I visited the expl3 manual and was scared witless... Hope you can understand that -- it's not a complaint, just an indication of the intellectual/experience distance from here to there. –  Brent.Longborough Mar 2 '12 at 9:02
Just seen this. To position myself, I'm very much at the Document Interface Layer (and above!), with occasional forays into the Design Layer. I have been known to dip into the Typesetting Layer (with fingers crossed and an Ave Maria), from whence I have occasionally been pulled, bedraggled and half-drowned, by friends here on TeX.SX. So for the moment, I'll wait for more thoughts from Frank, to whom my thanks. –  Brent.Longborough Apr 27 '12 at 20:45
On Frank's 'extend core functions' point, that would of course be very welcome. Contributed code would be very useful: feel free to send a message to the LaTeX-L list (or direct to me) with code for 'review'. Spreading 'LaTeX3 best practice' is important, I think. –  Joseph Wright Apr 27 '12 at 21:20
Frank, I thought this answer needed accepting; even though you're still working on it, it's already excellent. –  Brent.Longborough May 10 '12 at 11:22
thanks @Brent.Longborough. I guess I'm done now and I hope it helps you and other to perhaps participate in areas of interest. –  Frank Mittelbach May 13 '12 at 11:17