Is there a Visual Studio style tool/IDE?
In your comment you said you were more concerned about the "all in one" aspect, however if you want the best possible experience I think it's important to choose the right tool.
C++/Qt:
Qt Creator: A cross-platform integrated development environment (IDE) tailored to the needs of Qt developers. (I would recommend this option if you plan to be programming in C++).
Java:
Eclipse: This is pretty much the de facto Java IDE.
C#/.NET:
Mono: MonoDevelop is an IDE primarily designed for C# and other .NET languages.
My personal "IDE" is Gedit. It is minimal (similar to Notepad++ on Windows), but it gets the job done. It also supports plugins which can basically make it a true IDE. It supports most languages including C/C++, Java, C#, Python, Ruby, PHP, HTML, etc.
If you're using KDE as your desktop enviroment and don't want to run Gedit, you could also try Kate.
I don't have much experience with it myself (I personally like to work in gedit), but for the sake of completeness we really should mention Anjuta 
. It is part of the GNOME project, and includes many of the features you are interested in.
Focus on C/C++, but extensible with plugins. Some support for Python and Vala.
Integrated Glade user interface designer.
Version control integration with at least Git, CVS, and Subversion.
Project management and autotools support.
Integrated debugger including breakpoints, ect... Backed by gdb.
GTK+/GNOME Devhelp API help browser integration.
Valgrind plugin to profile programs for memory leaks.
I can't believe everyone's saying "use KDevelop" for C++.
In my experience, there is no better tool than Qt Creator.
It is:
- Fast
- Has a very flexible project manager
- Can be used for any C++ project - even non-Qt ones
- Has what I consider to be the best code-completion engine ever
- Integrates very extensively with the Qt framework (which I really recommend)
