+(also known as djgpp), GNU Make, rm, mv, and sed. See the remarks in
+config.bat for more information about locations and versions. The
+file etc/FAQ includes pointers to Internet sites where you can find
+the necessary utilities; search for "MS-DOS". The configuration step
+(see below) will test for these utilities and will refuse to continue
+if any of them isn't found.
+
+If you are building the MSDOG version of Emacs on an MSDOG-like system
+which supports long file names (e.g. Windows 95), you need to make
+sure that long file names are handled consistently both when you
+unpack the distribution and compile it. If you intend to compile with
+DJGPP v2.0 or later, and long file names support is enabled (LFN=y in
+the environment), you need to unpack Emacs distribution in a way that
+doesn't truncate the original long filenames to the DOS 8.3 namespace;
+the easiest way to do this is to use djtar program which comes with
+DJGPP, since it will note the LFN setting and behave accordingly.
+DJGPP v1 doesn't support long filenames, so you must unpack Emacs with
+a program that truncates the filenames to 8.3 naming as it extracts
+files; again, using djtar after setting LFN=n is the recommended way.
+You can build Emacs with LFN=n even if you use DJGPP v2, if some of
+your tools don't support long file names: just ensure that LFN is set
+to `n' during both unpacking and compiling.
+
+(By the time you read this, you have already unpacked the Emacs
+distribution, but if the explanations above imply that you should have
+done it differently, it's safer to delete the directory tree created
+by the unpacking program and unpack Emacs again, than to risk running
+into problems during the build process.)
+
+It is important to understand that the runtime support of long file
+names by the Emacs binary is NOT affected by the LFN setting during
+compilation; Emacs compiled with DJGPP v2.0 or later will always
+support long file names on Windows 95 no matter what was the setting
+of LFN at compile time. However, if you compiled with LFN disabled
+and want to enable LFN support after Emacs was already built, you need
+to make sure that the support files in the lisp, etc and info
+directories are called by their original long names as found in the
+distribution. You can do this either by renaming the files manually,
+or by extracting them from the original distribution archive with
+djtar after you set LFN=y in the environment.
+
+To unpack Emacs with djtar, type this command:
+
+ djtar -x emacs.tgz
+
+(This assumes that the Emacs distribution is called `emacs.tgz' on
+your system.)
+
+When unpacking is done, a directory called `emacs-XX.YY' will be
+created, where XX.YY is the Emacs version. To build and install
+Emacs, chdir to that directory and type these commands:
+
+ config msdos
+ make install
+
+Building Emacs creates executable files in the src and lib-src
+directories. Installing Emacs on MSDOS moves these executables to a
+sibling directory called bin. For example, if you build in directory
+/emacs, installing moves the executables from /emacs/src and
+/emacs/lib-src to the directory /emacs/bin, so you can then delete the
+subdirectories /emacs/src and /emacs/lib-src if you wish. The only
+subdirectories you need to keep are bin, lisp, etc and info. The bin
+subdirectory should be added to your PATH. The msdos subdirectory
+includes a PIF and an icon file for Emacs which you might find useful
+if you run Emacs under MS Windows.
+
+Emacs on MSDOS finds the lisp, etc and info directories by looking in
+../lisp, ../etc and ../info, starting from the directory where the
+Emacs executable was run from. You can override this by setting the
+environment variables EMACSDATA (for the location of `etc' directory),
+EMACSLOADPATH (for the location of `lisp' directory) and INFOPATH (for
+the location of the `info' directory).