You need DJ Delorie's port of GCC to DOS (DJGPP) to compile Gforth. DJGPP provides a DOS extender (GO32) that allows to use the 32-bit features of the 80386, but on the other hand it requires at least an 386. Gforth hasn't been tested with EMX, using EMX will require some changes in the console IO part. If you don't want to install this package (quite large), look for a binary distribution of Gforth for DOS. You must have a version of GNU make, because DOS make programs are likely to have problems with the Makefile. If you want to change Gforth, you may need GNU m4, too. If you don't bother and want to make it yourself, type configure There are no options for configure, because DOS can't execute a real configure script, all the configuring stuff is done on a real operating system. If you want to change something (e.g. use FORCE_REG or DIRECT_THREADED), you have to change the makefile yourself. Be careful! DOS command line arguments are limited to an overall size of 126 bytes, so adding a new define in the makefile will make it too long. In this case add the define at the beginning of machine.h instead, or create a file containing all extra options, and add @ to the defines (move the -DDEFAULTPATH-define into this file, and it will fit into the command line). After covering all inconveniences, type make gforth and after this finishes, type make We apologize for the inconveniences, we did not invent the 640k limit that prevents doing make straight forward. You may run out of memory anyway, because GCC eats up lots of it while compiling engine.c. Keep enough space free on your harddisk to allow GCC to swap. If you want to add some defines like -DFORCE_REG, type make gforth XDEFINES=-DFORCE_REG instead. Now you can check whether your shiny new Forth system works. Say make test You can run some benchmarks with make bench and compare them with the results in Benchres and in the manual. Don't try to do "make install", it won't work, either. It is not possible to "make dist" or "make bindist", too, because of the limitations of DOS command lines. Add the following entry to your Autoexec.bat: SET GFORTHPATH=:. Use / instead of \ in your gforth source directory. Another problem is, that Gforth uses : as path separator, and DOS pathes may look like D:/gforth. Sorry, there is no workaround for this now. For paper documentation, print gforth.ps (a Postscript file (300dpi fonts, i.e., it works, but does not produce best quality on better printers)), or say make gforth.dvi and print the resulting file gforth.dvi (you need TeX for that! But with TeX you can print it even if you don't have a Postscript printer nor Ghostscript). You could be able to make a html version of the document, but AFAIK there is no texi2html for DOS available, as there is no perl available.