Is DirectX a software exclusively for Windows?
If so which software does the work of DirectX in other OS?
Is DirectX a software exclusively for Windows?
If so which software does the work of DirectX in other OS?
DirectX is a collective name for a bunch of Microsoft APIs, including Direct3D, which is Window's 3D graphics API. Game developers can hook into these Microsoft APIs when they create their games, and when they do, the game will require DirectX to be installed when it is played.
So to answer your question, DirectX was intended to be used on Windows only. Since then, there have been attempts to get it working in Linux under Wine, with some relative success. Similarly, you can use winetricks to get some components running in Mac OSX.
As DirectX is a collection, there is no single competitor; however, OpenGL is the main alternative 3D graphics API, which would be a competitor to the Direct3D component of DirectX. OpenAL is the main alternative sound rendering API. Both of these are cross-language, multi-platform.
Yes, DirectX belongs only to Windows.
There are however other possibilites (I am positive I do not know them all):
Most of these are FOSS (Free, Open Source Software), but, most importantly, are cross-platform, i.e. they work on multiple platforms, Windows/Linux/Unix (including macOS).
On reading this article from Wikipedia I guess DirectX is only for Windows.
The first version of DirectX was released in September 1995 as the Windows Games SDK. It was the Win32 replacement for the DCI and WinG APIs for Windows 3.1. DirectX allowed all versions of Microsoft Windows, starting with Windows 95, to incorporate high-performance multimedia.
Since it's beginning it has been used only in Windows OS.
No, as of Windows Vista.
DirectX is part of the operating system, while you may have some luck emulating it, expect less than optimal results.