Free directx software for windows

a free DirectX uninstaller for Windows DirectX Buster is a DirectX uninstaller for Windows 9X, ME and W2K.
It uninstalls DirectX from version 5 up to version 8.1 without any problems.
This tool may also work properly on later DirectX versions (e.g. DirectX 9).

This is a conversion of Microsofts DirectX 6 C++ headers for Borland-Delphi (Version 2-4)

Develop DirectX plug-ins using Borland Delphi. Delphi DirectX SDK will help you develop DirectX plug-ins using Borland Delphi.
If you are fluent in C++, you should check out the Cakewalk DirectX Wizard. If you want to dig in further, the Sony Audio Plugin Development Kit (formerly known as Sonic Foundry PIDK) has lots of valuable doco and sample code.
Finally, the DirectX SDK that Microsoft ships with MSDN is the ultimate resource, where you can see the C++ source code for the DirectShow filter classes.
However, if you would prefer to use Delphi and avoid messing around with COM and the DirectShow interfaces, the DDX SDK V4 is for you.

If you want to grab the microphone and impress all of your friends with your Karaoke skills, then AnalogX DirectX Vocal Remover is for you! The vocal remover will work on 90% of the stereo recordings available on the market...
The vocals are not completely removed in most cases, but they are low enough that you usually can barely hear them. Currently the program removes vocals much in the same way the hardware devices do - by making the assumption that vocals are usually recorded equally on both channels, while the music itself is not.
By making this assumption, you can remove whatever is the same in both channels by changing their phase relationship by 180 degrees, and then summing the two channels. The plugin REQUIRES a stereo input, if you do not give it the left and right channels, it will not process the incoming stream, but instead just pass it through There will be some big improvements to this in the future versions, as this is only the beginning...
Now, for certain styles of music you might end up removing more than the
vocals - there really is no way around this - but there are some benefits to
this as well. I use this technique all the time to rip out drum loops, and
depending on the style of music you can use this to easily rip out specific
instruments as well!
In order to use this plugin, you must have DirectX 6 or greater installed, as
well as DirectX Media. You must also have a DirectX audio-compatible music
application (like Paris, WaveLab, Cakewalk, etc) installed in order to use the
plugin. It requires a stereo (2 channel) stream to work properly, at either
16bit or 32bit.

DirectX Tweaker is a tool that acts like an interface between DirectX and/or Direct 3D and the program that originally uses the Direct 3D interfaces.
This allows to change or log all actions of the Direct 3D interface.
DirectX Tweaker serves as a host for many different plug-ins, which provide different functions each.
With this kind of modular approach it is very easy to design special modules to interact with Direct 3D.