Visual Basic etc Download

What are you asking for? The download link for the compiler (or appliaction) you listed out?

Visual Basic 6.0
It is a proprietary software and you cannot download for free legally, however, you may search for it at Google, or, if you are not required to use that version, you may use the newest Visual Basic Express, which can be downloaded for free in Microsoft.

C / C++
There is a huge number of C / C++ compilers available in different platform. Assuming you are using Windows and would like to develop Windows application, you may use Visual C++ Express or MinGW, the former one is delivered with Integrated Develop Environment (IDE), and the latter one is a standalone compiler, but you may use it with other IDEs and libraries, for IDE, you may use it with Dev-C++, or if you like to develop GUI application, in my opinion there is a easy-to-use C++ GUI library called Qt, its SDK includes its own IDE, MinGW compiler and the GUI library.

JavaScript
It is a web-browser scripting language and requires no compiler or specific editor, you may use your favorite text editor to embed JavaScript into your web pages, just make sure your script starts with .If you would like to link the script file, you may write

Java
You need Java Development Kit (JDK) to compile Java program, you may use any text editor to edit source file of Java programs. If you want a IDE for Java, you may use jGRASP.

.net
It is not a programming language but a framework required by Visual Studio (starting from 2003), it is delivered with any Visual Studio language tool.


2010-04-25 18:55:06 補充：
Each of the software / languages / tools you have asked are explained and links are included as hyperlinks (if applicable).

If you cannot access those links, here's the URL of each link I have included:

2010-04-25 18:55:19 補充：
- Visual Basic Express / Visual C++ Express
[ http://www.microsoft.com/express/Windows/ ]

- MinGW Compiler
[ http://www.mingw.org/ ]

- Dev-C++ IDE
[ http://sourceforge.net/projects/dev-cpp/ ]

- Qt C++ GUI SDK
[ http://qt.nokia.com ]