What is LaTeX3 correcting in LaTeX2e? And, updates 2021 on LaTeX implementation on small mobiles OS? [duplicate]

Question

There are so many things wrong with LaTeX2e according to the latest discussion, Why is LaTeX3 taking so long to come out?, from documentation to speed, inflexible kernel, etc. We are perhaps waiting in vain for LaTeX3 and expl3 full deployment but what is called "gentle re-fractory" see What's the current state of LaTeX3 (2020)?.

What are the deficiency and features in LaTeX2e that LaTeX3 project hence "gentle refractory" and L3 programming seeks to provide solution to (and how significant )? Surely separating design and codes will be great, but LaTeX3 project must prove it's relevance in terms of quality of extension, alternate solutions, user interface and better features than LaTeX2e!

Secondly, I haven't seen any basic and compilable Tex for mobiles OS like android. Many use online Tex Editors and tools or snippets like Overleaf. Will need latest implementation of TeX on say android OS and MacOS.

In my opinion, LaTeX3 project has taken so much time, (more than 20years since the project started), and surlely new issues of change due to time will continually postpone "getting perfected for release" Sure, it won't be able to replace LaTeX2e and conTeXt but "soft refractory" for possible modernization I find information on the following discussions partly useful and educating..

• What's the current state of LaTeX3 (2020)?

• What are the best practices for programmatic interaction between LaTeX3 and LaTeX2e?.

• What is the e specifier for LaTeX3 and where is it documented?.

Am currently working on mobile implementation of TeX-Latex.

Answer 1

And, on implementing Tex ( editing and compiling) on small mobile and tablet PC,

• there is a work by Clerk Ma "TeXLive for Android. " (http://code.google.com/p/texlive-for-android/ ) but with unresolved issues relating to font and Bibliography, and installing on Android 5.0 and above.

• VerbTeX Pro is another for editing latex documents, which gives a nice android-friendly UI . Downloable on google play. (https://www.google.com/url?q=https://play.google.com/store/apps/details%3Fid%3Dverbosus.verbtex%26hl%3Den%26gl%3DUS%26referrer%3Dutm_source%253Dgoogle%2526utm_medium%253Dorganic%2526utm_term%253Dmobile%2Btex%2Beditor&sa=U&ved=2ahUKEwit8pWl5vDvAhVFhf0HHcKVBDMQFjAAegQIARAB&usg=AOvVaw2pH76F8ZYmJ0MSWN-wQD-0 )

• Tex portal also on google play.

Am personally making my own [a collaborative lab work] by extracting only essential packages from Texlive and will be working on minimum packages needed and compatible fonts(Asia, Africa, Europe) as was kindly suggested to me in a chat.

You would like to help? You are most welcome! Please, let me know in whatever capacity you could be of help - similar works or informed-direction. Thanks a lot

Answer 2

To some extent, and am really happy with the discussion at What's the current state of LaTeX3 (2020)? and log report showing the < LaTeX2e <2020-10-01> patch level 2 L3 programming layer <2020-10-27> xparse <2020-03-03> >. Which shows that it is already being introduced to LaTeX2e, in "a gentle re-fractory" sort of principle.

However ,that was as situation was last year October-November 2020. It seems we are never going to see LaTeX3 as a standalone product or a name replacing LaTeX2e.

It will be good if @Fischer can discribe what "problems" or deficiency in LaTeX2e and conTeXt that LaTeX3 project hence "gentle refractory" seeks to provide solution (and how significant?)

Notes: LaTeX Project (used to be LaTeX3 project in alias) has made the decision to drop the idea of a separate LaTeX3 format that would exist in parallel to LaTeX2e, but instead decided to gradually modernize LaTeX to keep it competitive in today’s world while maintaining compatibility methods for older documents. [https://www.latex-project.org/latex3/]

As part of this change of focus the following major improvements have been introduced in the last few years:

• 2018: Full support for Unicode input; UTF-8 became the default encoding in LaTeX;
• 2019: Introduction of the LaTeX development formats to allow people to try out upcoming releases with ease;
• 2020: Integration of the L3 programming layer into the LaTeX format; the first uses of this layer inside the format are a new general hook management system for LaTeX, and the xparse document commands (formerly available as a package); Interface extensions to NFSS (The LaTeX font selection scheme) to better support modern fonts (OpenType and others).

And recall that at the TUG conference 2020, the group announced the start of a multi-year project (financially supported in part by Adobe) to provide LaTeX support for the straightforward production of ‘tagged PDF’. Please note that conTeXt is an independant format and which does not relate to the LaTeX Team. The main project being worked-on by the Team is the tagged pdf project, which involves a lot of other tasks too. See https://www.latex-project.org/publications/indexbyyear/2020 .

Hope, and for better days and more intuitively productive document Typesetting System.