which programming language is most widely using by the software devolopers
to devolop software like, any OS,application software,IDEs ,computer and mobile applications.?

There is no one language to do all that. Writing desktop applications will require different languages and compiler than writing web based applications. And writing mobile applications is still different from either of the other two. First determine what it is that you want to write and then select a language and compiler (if needed) to produce it. There's no "one size fits all" here.

Here is my version of simplified answer:

to devolop software like:
1. any OS - C/C++
2. application software - Any Language Can do!
3. IDEs - Any language can do (CodeLite in C++, Wing IDE in Python, IntelliJ Idea in Java et al)
4. computer - Answered as no 2
5. mobile applications - Most of themw will do (C++ in Symbian, Python in S60, Java ME et al)

So be specific to receive specific answers ;)

That is a bit field, so I can't really speak for all of it since I don't know.
First off there are not that many completely distinct OS , we have windows, unix (several flavours0, linux, BSD/Mac OS-x then stuff like OS-9 [it is in things like microwaves, digital watches, videos, washing machines -- if anyone knows the install base numbers please let us know! -- I have half an idea it might be the most popular OS, but don't know.

All of those have some assembly, a lot of C, some like windows have C++, which might be the dominate coding language (?). Cool operating systems like VMS, had BLISS which was the popular operating system language BEFORE C came along!!!

Application programming: Well that is just about everything, from high end functional codes, down to hacked together perl. In that context the correct thing to ask is what code base is most popular in a given field. E.g. if you want to be a CERN applications programmer, apart from getting your head round some scary physics, a large amount of that stuff is C++. Similarly, games are a lot of C++, you will find lots of java/javascript/php etc in web-based stuff.

The real question is why do you want to know, and specifically in what area do you want to know. That would give a much more focused answer. [Note: idol curiosity is perfectly acceptable...]

Since you posted this to the C++ forum, the general overall, how has paying jobs coding would indicate that, java leads and c++ is around the 15% mark.