There is only 1 C++ and 1 C (at least if you mean the standard).
There are many compilers for those languages but they all accept the same basic source code.
If you mean the additional libraries that come with those compilers, yes there are many differences between those but that's not the core language.
Same with the debuggers and editors, those are not the language but (merely) tools supplied by the compiler creator (or a third party in which case they may work with many compilers) to make life easier.
C++ isn't an extension of C per se either. It's a new language building on C which happens to accept (most) C source as valid code for itself.
If you don't know who created the language or why it's not called C+ those questions are both answered on the website of the language creator which is here: http://www.research.att.com/~bs/C++.html
I can tell you the name is effectively a bit of a pun :)