This directory contains compilation instructions for various libraries and
programs used by Macaulay2.  A library is code linked into the Macaulay2 binary
"M2", whereas a program is code that runs separately or a library that gets
linked into a program and does not get linked into M2.  The programs are
distributed with their own licenses; we've made notes about that in the file
../LICENSING-NOTES.

Some of the libraries are sharable, so the various other makefiles takes care
of adding the appropriate directories to the value of the environment variables
LD_LIBRARY_PATH (for unix) and DYLD_LIBRARY_PATH (for Mac OS), and there are
two shell scripts, both called M2, each of which adds one directory to the
path.  The one at the top level of the build directory adds
libraries/final/lib, where the dynamic libraries are deposited after being
built, and the one in usr-dist/$ARCH/bin/ adds the directory
usr-dist/$ARCH/lib/, where they are eventually copied.

To add a new program:

     - add a directory here with the same name as the library, together with an
       appropriate file Makefile.in.  Use the other Makefile.in files as
       models.

     - Document the dependencies in the appropriate comment in ../configure.ac.
       Add the program to the list "PROGLIST".

     - add documentation about the program to
       ../Macaulay2/packages/Macaulay2Doc/overview3.m2, with a link to it from
       the node called "Copyright and license".  Use the nodes for the other
       programs as models.  Describe the licensing model there.

     - a licensing note to ../LICENSING-NOTES

To add a new library:

     - add a directory here with the same name as the library, together with an
       appropriate file Makefile.in.  Use the other Makefile.in files as
       models.

     - add code to ../configure.ac to check for the presence of the library and
       arrange for it to get built if not present.  Document the dependencies 
       in the appropriate comment.  Add the library to the list "LIBLIST".

     - add code to ../Macaulay2/d/version.dd to add the version number of
       the library used to the hashtable "version"

     - add code to ../Macaulay2/d/version.dd to add the version number of
       the library used to the hashtable "version",
       displayable at top level

     - add code to ../Macaulay2/d/startup.m2.in to add the version number of
       the library and the copyright status to the string "copyright",
       displayable at top level

     - add documentation about the library to
       ../Macaulay2/packages/Macaulay2Doc/overview3.m2, with a link to it from
       the node called "Copyright and license".  Use the nodes for the other
       libraries as models.  Describe the licensing model there.

     - verify that the code of the library is licensed in such a way that we
       may link it our program and distribute the resulting binary under
       GNU GPL 3.

     - add a licensing note to ../LICENSING-NOTES
