This directory is for extensions to SBCL. They aren't necessary for
core SBCL functionality, or else they'd be built into the main SBCL
binary automatically. And they're not portable Common Lisp, or they'd
be put elsewhere (see http:https://sbcl.sf.net/libs.php for pointers)

There are two kinds of contrib module in this directory:

  * Newer contrib modules conform to the contrib standard (see 
    STANDARDS) and are automatically built and installed along with
    SBCL itself.  Each of these is in its own subdirectory with a
    Makefile, and can be loaded with REQUIRE.

  * Older standalone files in the contrib directory itself are
    effectively unpackaged and may or may not work with the current
    SBCL version.

Some good candidates for future extensions here are:
  * bindings to existing foreign libraries (e.g. to a regexp library
    like PCRE, or to a compression library like zlib, or to a graphics
    library like Tk)
  * new libraries (e.g. a CORBA interface)
  * low-level hooks into SBCL needed to interface it to some wrapper
    system (e.g. to interface to a graphical debugger of some sort)
  * a too-alpha-to-be-supported-yet tree shaker

SBCL extensions of less general interest, e.g. a binding to the C
interface of the Oracle RDBMS, or particularly large extensions, e.g.
big graphics frameworks, can also be associated with the SBCL project,
but instead of being included in this directory as part of the
distribution, they will be made available or linked to on the SBCL
project web site.