2     Structure of TeX Live
The main two installation scripts for Unix and Mac OS X are install-tl.sh and install-pkg.sh. We discuss
them in section 3 on p. 13. Here, we describe the structure and contents of TeX Live.
   2.1     Multiple distributions: live, inst, demo
As of 2003, space limitations of CD-ROM format have forced us to divide TeX Live into three distributions, as
follows.
     
- 
live 
- a complete, runnable system on DVD; it is too large for CD-ROM. (The DVD also includes a snapshot
     of the CTAN repository, completely independent of TeX Live.)
     
- 
inst(allable) 
- a complete system on CD; in order to make it fit, we had to compress everything we could.
     Therefore, it is not possible to run TeX directly from the installable CD, you have to install it to disk
     (hence its name). Installation is described in subsequent sections.
     
- 
demo 
- a  live  system  runnable  directly  from  CD;  in  order  to  make  this  fit,  we  omitted  the  very  large
     collection  of  CJK  (Chinese,  Japanese,  Korean)  language  support,  support  for  typesetting  music,
     some less-commonly used fonts, and included executables only for Linux, Mac OS X, and Windows
     systems.
     
You can tell which type of distribution you’re in by looking for a 00type.TL file in this top-level
directory.
   2.2     Top level directories
Here is a brief listing and description of the top level directories in the TeX Live distribution.
                                                                                 
                                                                                 
   | bin | The TeX system programs, arranged by platform.                                                            | 
| Books | Examples from some of the books about TeX (see Books/README).                              | 
| FAQ | Current versions of major FAQ collections.                                                                      | 
| info | A few manuals in GNU Info format, where available.                                                      | 
| MacOSX | Supporting software for Mac OS X (see section 5 on p. 32).                                           | 
| man | Unix man pages.                                                                                                                | 
| source | The  source  of  all  programs,  including  the  main  Web2C  TeX  and  METAFONT
  distributions. These are stored in a bzip2-compressed tar archive.                                    | 
| support | assorted auxiliary packages and programs. These are not installed by default. This
  includes Ghostscript, netpbm, and assorted editors and TeX shells.                                | 
| texmf | root of installed packages, fonts, config files, etc.                                                             | 
| usergrps | Material about a few of the TeX user groups. (Visit http://tug.org/usergroups.html for
  a current list.)                                                                                                                     | 
| xemtex | The  XEmacs  editor  and  other  support  programs  for  Windows  (see  section 6.3  on
  p. 38). These programs generally come pre-installed on Unix systems, or are at least
  easy to compile.                                                                                                                 | 
|  | 
   2.3     Extensions to TeX
TeX Live contains three extended versions of TeX:
     
- 
e-TeX 
- adds a small but powerful set of new primitives (related to macro expansion, character scanning,
     classes  of  marks,  additional  debugging  features,  and  more)  and  the  TeX--XE T  extensions  for
     bidirectional  typesetting.  In  default  mode,  e-TeX  is  100%  compatible  with  ordinary  TeX.  See
     texmf/doc/etex/base/etex_man.pdf. e-TeX is now the default for LaTeX and pdfLaTeX.
     
- 
pdfTeX 
- writes Acrobat PDF format as well as DVI. The LaTeX hyperref package has an option ‘pdftex’
     which turns on all the program features. See texmf/doc/pdftex/pdftex-l.pdf and texmf/doc/
     pdftex/base/example.tex.
     
- 
 (Omega) (Omega)
- based  on  Unicode  (16-bit  characters),  thus  supports  working  with  almost  all  the  world’s
     scripts simultaneously. It also supports so-called ‘ Translation Processes’ (OTPs), for performing
     complex  transformations  on  arbitrary  input.  See  texmf/doc/omega/base/doc-1.8.tex (not
     completely up-to-date). Translation Processes’ (OTPs), for performing
     complex  transformations  on  arbitrary  input.  See  texmf/doc/omega/base/doc-1.8.tex (not
     completely up-to-date).
   2.4     Other notable programs in TeX Live
Here are a few other commonly-used programs included in TeX Live:
     
- 
 bibtex 
- bibliography support.
     
- 
 makeindex 
- index support.
                                                                                 
                                                                                 
     
- 
 dvips 
- convert DVI to PostScript.
     
- 
 xdvi 
- DVI previewer for the X Window System.
     
- 
 dvilj 
- HP LaserJet driver.
     
- 
 dv2dt, dt2dv 
- convert DVI to/from plain text.
     
- 
 dviconcat, dviselect 
- cut and paste pages from DVI files.
     
- 
 dvipdfm 
- convert DVI to PDF, an alternative approach to pdfTeX (mentioned above). See the ps4pdf and
     pdftricks packages for still more alternatives.
     
- 
 psselect, psnup, . . . 
- PostScript utilities.
     
- 
 lacheck 
- LaTeX syntax checker.
     
- 
 texexec 
- ConTeXt and PDF processor.
     
- 
 tex4ht 
- TeX to HTML converter.