Things needed for compilation.

SDL 
    The Simple DirectMedia Library available at http://www.libsdl.org
    The dll distributed with the windows version of DOSBox is slightly
    modified. You can find the changes in the sourcepackage of DOSBox
    (src/platform/sdl-win32.diff). If you want the patched sourcetree
    send us an email. (see README)
    Licensed under LGPL
    Note that only version 1.2 and its subversions (1.2.8, 1.2.13 etc.)
    are currently supported.

Curses (optional)
    If you want to enable the debugger you need a curses library.
    ncurses should be installed on just about every unix distro.
    For win32 get pdcurses at http://pdcurses.sourceforge.net
    License: Open source

Libpng (optional)
    Needed for the screenshots.
    For win32 get libpng from http://gnuwin32.sourceforge.net/packages.html
    See http://www.libpng.org/pub/png/ for more details.
    License: Open Source

Zlib (optional)
    Needed by libpng.
    For win32 get libz (rename to zlib) from http://gnuwin32.sourceforge.net/packages.html
    See http://www.zlib.net for more details.
    License: Open Source

SDL_Net (optional)
    For modem/ipx support. Get it from http://www.libsdl.org/projects/SDL_net/
    Licensed under LGPL

SDL_Sound 
    For compressed audio on diskimages. (optional)
    This is for cue/bin cdrom images with compressed (mp3/ogg) audio tracks.
    Get it from http://icculus.org/SDL_sound
    Licenced under LGPL

ALSA_Headers
    (optional)
    for Alsa support under linux. Part of the linux kernel sources
    Licensed under LGPL

If you want compile from developer sources (SVN) under a unix system, you'll also need 
automake (>=1.6), autoconf(>=2.50). Should be available at http://www.gnu.org

For building on unix systems.
If you are building from developer sources run ./autogen.sh first before doing the following.

1. ./configure
2. make

In step 1 you could add the following switches:
--enable-debug 
        enables the internal debugger. --enable-debug=heavy enables even more 
        debug options. DOSBox should then be run from a xterm and when the sdl-
        window is active press alt-pause to enter the debugger.

--enable-core-inline
        enables some memory increasing inlines. This greatly increases 
        compiletime for maybe a increase in speed.

--disable-fpu
        disables the emulated fpu. Although the fpu emulation code isn't 
        finished and isn't entirely accurate it's advised to leave it on. 

--disable-fpu-x86
        disables the assembly fpu core. Although relatively new the x86 fpu 
        core has more accuracy then the regular fpu core. 

--disable-dynamic-x86
        disables the dynamic x86 specific cpu core. Although it might be 
        be a bit unstable, it can greatly improve the speed of dosbox on x86 
        hosts.
        Please note that this option on x86 will result in a different
        dynamic/recompiling cpu core being compiled then the default.
        For more information see the option --disable-dynrec

--disable-dynrec
        disables the recompiling cpu core. Currently x86 and x86_64 only.
        You can activate this core on x86 by disabling the dynamic-x86 core.

--disable-dynamic-core
        disables all dynamic cores. (same effect as 
        --disable-dynamic-x86 --disable-dynrec)

--disable-opengl
        disables OpenGL-support (output mode that can be selected in the
        DOSBox configuration file).

--disable-unaligned-memory
        disables unaligned memory access.

Check the src subdir for the binary.

NOTE: If capslock and numlock appear to be broken. open
src/ints/bios_keyboard.cpp and go to line 30 and read there how to fix it.


Build instructions for VC++6 
Don't use VC++ 6: it creates faulty code in core_normal.cpp
Later Visual Studio versions work fine (vs2003/.net up to vs2010)