You need DJ Delorie's port of GCC to DOS (DJGPP 2.0) to compile Gforth. DJGPP provides a DPMI client that allows to use the 32-bit features of the 80386, but on the other hand it requires at least a 386. A DPMI host is also part of the DJGPP 2.0 package, this is required if you don't have a DPMI host yourself (Windows/OS/2/Linux DOS-box, Quemm or others). 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 the DJGPP 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 configure has the following useful parameters: --enable-force-reg Use explicit register declarations if they appear in the machine.h file. This can cause a good speedup, but also incorrect code with some gcc versions on some processors (default disabled). --enable-direct-threaded Force direct threading. This may not work on some machines and may cause slowdown on others. (default processor-dependent) --enable-indirect-threaded Force indirect threading. This can cause a slowdown on some machines. (default processor-dependent) After covering all inconveniences, type make 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.