MonoDevelop is a free IDE for Gnome (a desktop environment for Unix platforms like Linux) for developing C# and other .net languages.

MonoDevelop has many features as well as the usual code completion and project support. MonoDevelop allows for the creation of GTK# applictions and has a built in visual designer with its own widget library and can even import Glade projects.

Included in MonoDevelop IDE is also a database manager where you can create and execute queries as well as allowing you to create databases, tables and procedures.

Other great features found in MonoDevelop are versioning control. Visual Studio integration, Nunit unit testing library and ASP.net web projects.