Hello all,

Following the 2015-01-01 LaTeX2e update the team have been working on
further 'modern' engine support. In particular, we have been examining
how to integrate functionality provided by the contributed "luatexbase"
into the kernel. This package provides allocators for a range of
LuaTeX-specific registers and Lua functions which require similar
low-level support.

Working with the authors of luatexbase we have now established a clear
idea of what needs to be adjusted in the kernel and what should remain
in the contributed tree. Our current approach is to add the allocator
code to the kernel, with this also available as a new "ltluatex.tex"
file for plain TeX users and for those with older kernels. The concept
of stacks for category code tables will be made available as a new
package ctablestack, while we plan to provide a 'transitional'
"luatexbase.sty" to allow a smooth transition from the existing
contributed code to the new kernel support. (We are thankful to the
current luatexbase authors for both their code and keenness to move to
this new position).

The kernel part of the code is available from

  http://latex-project.org/svnroot/latex2e-public/trunk/base/ltluatex.dtx

whilst the package part is available from

  https://github.com/josephwright/ltluatexsupp

(The latter will be supported by David Carlisle and me rather than
formally by the team as a whole.)

The team have been working carefully to check that the changes we are
planning will largely be transparent to end users. Some package authors
will already have had requests from the team to make minor code
adjustments to help with this process.  Experience with the previous
LaTeX2e update suggests that significant testing will not occur until a
CTAN release of the code, but we would welcome any feedback at this stage.

Importantly, the team have been carefully considering to the current
naming of LuaTeX-specific primitives. Whilst we understand the logic in
giving them the \luatex... prefix, but we feel that this is overall more
of a complicating factor than an aid. In particular, whilst LuaTeX is
not yet 'stable' the addition of new primitives is carefully managed and
unlikely to impact on existing documents. We are therefore currently
planning to drop the prefixing and provide the LuaTeX primitives with
their native names. We have been working with package authors to assist
in this transition, which can be reverted using the latexrelease system.

In addition to these changes, the new LaTeX2e release will feature bug
fixes in the tools tree and an update of the Unicode data file
introduced in the last release to incorporate Unicode 8.0.0 changes.

The current plan is that a release will occur in October.

Regards,

Joseph