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+% language=uk
+
+\environment luatex-style
+\environment luatex-logos
+
+\startcomponent luatex-introduction
+
+\startchapter[title=Introduction]
+
+This is the reference manual of \LUATEX. We don't claim it is complete and we
+assume that the reader knows about \TEX\ as described in \quotation {The \TEX\
+Book}, the \quotation {\ETEX\ manual}, the \quotation {\PDFTEX\ manual}, etc.
+Additional reference material is published in journals of user groups and
+\CONTEXT\ related documentation.
+
+It took about a decade to reach stable version 1.0, but for good reason.
+Successive versions brought new functionality, more control, some cleanup of
+internals and experimental features evolved into stable ones or were dropped.
+Already quite early \LUATEX\ could be used for production and it was used on a
+daily basis by the authors. Successive versions sometimes demanded a adaption to
+the \LUA\ interfacing, but the concepts were unchanged. The current version can
+be considered stable in functionality and there will be no fundamental changes.
+Of course we then can decide to move towards version 2.00 with different
+properties.
+
+Don't expect \LUATEX\ to behave the same as \PDFTEX ! Although the core
+functionality of that 8 bit engine was starting point, it has been combined with
+the directional support of \OMEGA\ (\ALEPH). But, \LUATEX\ can behave different
+due to its wide (32 bit) characters, many registers and large memory support.
+There is native \UTF\ input, support for large (more that 8 bit) fonts, and the
+math machinery is tuned for \OPENTYPE\ math. There is support for directional
+typesetting too. The log output can differ from other engines and will likely
+differ more as we move forward. When you run plain \TEX\ for sure \LUATEX\ runs
+slower than \PDFTEX\ but when you run for instance \CONTEXT\ \MKIV\ in many cases
+it runs faster, especially when you have a bit more complex documents or input.
+Anyway, 32 bit all||over combined with more features has a price, but on a modern
+machine this is no real problem.
+
+Testing is done with \CONTEXT, but \LUATEX\ should work fine with other macro
+packages too. For that purpose we provide generic font handlers that are mostly
+the same as used in \CONTEXT. Discussing specific implementations is beyond this
+manual. Even when we keep \LUATEX\ lean and mean, we already have enough to
+discuss here.
+
+\LUATEX\ consists of a number of interrelated but (still) distinguishable parts.
+The organization of the source code is adapted so that it can glue all these
+components together. We continue cleaning up side effects of the accumulated
+code in \TEX\ engines (especially code that is not needed any longer).
+
+\startitemize[packed]
+    \startitem
+        Most of \PDFTEX\ version 1.40.9, converted to \CCODE. Some experimental
+        features have been removed and some utility macros are not inherited as
+        their functionality can be done in \LUA. The number of backend interface
+        commands has been reduced to a few. The extensions are separated from the
+        core (which we keep close to the original \TEX\ core). Some mechanisms
+        like expansion and protrusion can behave different from the original due
+        to some cleanup and optimization. Some whatsit based functionality (image
+        support and reusable content) is now core functionality.
+    \stopitem
+    \startitem
+        The direction model and some other bits from \ALEPH\ RC4 (derived from
+        \OMEGA) is included. The related primitives are part of core \LUATEX\ but
+        at the node level directional support is no longer based on so called
+        whatsits but on real nodes. In fact, whatsits are now only used for
+        backend specific extensions.
+    \stopitem
+    \startitem
+        Neither \ALEPH's I/O translation processes, nor tcx files, nor \ENCTEX\
+        can be used, these encoding|-|related functions are superseded by a
+        \LUA|-|based solution (reader callbacks). In a similar fashion all file
+        \IO\ can be intercepted.
+    \stopitem
+    \startitem
+        We currently use \LUA\ 5.2.*. At some point we might decide to move to
+        5.3.* but that is yet to be decided. There are few \LUA\ libraries that
+        we consider part of the core \LUA\ machinery, for instance \type {lpeg}.
+        There are additional \LUA\ libraries that interface to the internals of
+        \TEX.
+    \stopitem
+    \startitem
+        There are various \TEX\ extensions but only those that cannot be done
+        using the \LUA\ interfaces. The math machinery often has two code paths:
+        one traditional and the other more suitable for wide \OPENTYPE\ fonts.
+    \stopitem
+    \startitem
+        The fontloader uses parts of \FONTFORGE\ 2008.11.17 combined with
+        additional code specific for usage in a \TEX\ engine. We try to minimize
+        specific font support to what \TEX\ needs: character references and
+        dimensions and delegate everything else to \LUA. That way we keep \TEX\
+        open for extensions without touching the core.
+    \stopitem
+    \startitem
+        The \METAPOST\ library is integral part of \LUATEX. This gives \TEX\ some
+        graphical capabilities using a relative high speed graphical subsystem.
+        Again \LUA\ is used as glue between the frontend and backend. Further
+        development of \METAPOST\ is closely related to \LUATEX.
+    \stopitem
+\stopitemize
+
+The \TEXLIVE\ version is to be considered the current stable version. Any version
+between the yearly \TEXLIVE\ releases are to be considered beta. The beta
+releases are normally available via the \CONTEXT\ distribution channels (the
+garden and so called minimals).
+
+\blank[1*big]
+
+Hans Hagen, Harmut Henkel, \crlf
+Taco Hoekwater \& Luigi Scarso
+
+\blank[3*big]
+
+\starttabulate
+\NC Version  \EQ \currentdate \NC \NR
+\NC \LUATEX  \EQ Snapshot \number\luatexversion.\luatexrevision \NC \NR
+\NC \CONTEXT \EQ \contextversion \NC \NR
+\stoptabulate
+
+\stopchapter
+
+\stopcomponent