Free Development Tools
The Open Watcom site
offers a free C++ compiler, which includes WLink, Wasm and WD, a DPMI debugger
which is compatible with HX.
are all based on GCC, the GNU C/C++ compiler frontend.
MinGW and CygWin are for Win32, DJGPP is for 32bit DOS, EMX is for OS/2 + 32bit DOS.
The GCC C compiler is good and produces compact code, the C++ version
tends to bloat the binaries a bit.
HX supports MinGW, CygWin and DJGPP. EMX has not been tested.
The Digital Mars C++ compiler
is free and the package includes OPTLINK, a very good OMF linker.
On the LADSoft site you may get
the free and very good OMF linker VALX.EXE. Also somewhere on this site one may find the CC386 C compiler,
which is shipped with several DOS extenders, but HX is compatible with it as well.
Last but not least the site hosts GRDB, a debugger for DOS and DPMI applications.
Written by David Lindauer.
Pelles C is a good and free C compiler.
An IDE is included, as well as a full toolset (POLINK, POLIB, PORC) to build Win32 binaries.
- The MS Visual C++ Toolkit 2003 - which included the MS optimizing Visual C++ compiler - is regretably no longer downloadable.
Microsoft now recommends to download the Visual C++ 2008 Express Edition,
which is "bloatware" IMO.
- Borland also has a free C++ compiler to offer in the
C++ Turbo Explorer package, but will force you to answer some questions first.
Support for DOS extended applications is NOT included there, but luckily HX
can fully replace this missing feature (;-)). Regretably the licence coming with this package
doesn't allow commercial software development, so you cannot sell any binary created by the compiler.
- Free Pascal
is pretty much Delpi compatible and is free (GPL).
- Virtual Pascal
is 'officially dead'. But it is a very good, free compiler with a nice and fast IDE
(Turbo Vision style).
is included here. The license requires that you own MS VC 6.
Masm v8 can be used, but IIRC the license is pretty restricted.
NASM (Netwide Assembler)
is a free assembler (BSD license) which runs on Linux, Win32 and DOS. Supports 16-, 32- and
64-bit, and lots of output formats. It runs a bit slow and
the macro capabilities are pretty limited compared to MASM's.
FASM (Flat Assembler)
is a free assembler which runs on Win32, DOS and Linux. Supports 16-, 32- and
64-bit assembly. OMF output format isn't supported. IMO FASM's assembly
syntax and macro capabilities are the best among the "Nasm-style" assemblers.
is a rewrite of NASM. BSD license.
POASM in included in PellesC.
It's an assembler which understands Masm syntax to some degree, but is premature and
restricted to FLAT memory model (32- and 64-bit).
is a freeware assembler, restricted to FLAT memory model (32- and 64-bit) and Windows programming.
SolASM (Solar Assembler)
is a freeware assembler, supports 16-, 32- and 64-bit, and output formats Binary, Omf, Coff, Elf, Macho.
LZASM (Lazy Assembler)
is a free assembler which runs on Win32 and DOS. Supports TASM 'IDEAL' syntax.
is a free BASIC compiler (Win32 and DOS).
From Sudley Place Software you may get
QLINK, an OMF linker and 386SWAT, a 386 debugger. Also take a look at DPMIONE, their
free DPMI 1.0 server.
The WDOSX site
offers another free PE based DOS extender, which you may compare with HX.
(Not under development anymore.)
DosWin32 is -like WDOSX - a HX competitor.
Some of the docs are in russian only.
- A site where many free compilers, assemblers, debuggers and dos extenders are listed is
Free Programmers Resources.
A similiar site with a more general approach, but without DOS extenders is
Free Programming Resources.