SharpDevelop 4 - Portable Visual Studio with full support

Supported Programming Languages:

C# (Code Completion, Windows Forms Designer)
VB.NET (Code Completion, Windows Forms Designer)
Boo (Code Completion, Windows Forms Designer)
IronPython (Code Conversion, Windows Forms Designer, partial Code Completion)
IronRuby (Code Conversion, Windows Forms Designer)
F#

Designers:

Windows Forms
Windows Presentation Foundation (WPF)
Entity Framework (EF EDM Designer)

Developer Productivity:

Refactoring
Parallel build support for multi-core machines
NuGet and T4 support
Multi-framework targetting (.NET 4.0, as well as 2.0, 3.0 and 3.5)
Code Autoinsert More information
Starts from a USB memory stick (More information)
Read-only project support (More information)
Full MSBuild support

Quality Tools:

Integrated Debugger (including dynamic debugging features)
Code Analysis (FxCop)
Unit Testing (NUnit)
Code Coverage (PartCover)
Profiler (Roadmap)
Integrated Subversion support (TortoiseSVN)
Integrated Git support
StyleCop addin (More information)
Setup projects (WiX, More information)
SharpDevelop Reports .NET open-source reporting solution (More)
Parser-based code converter (Online Code Converter)
XML "code completion"
Documentation generation (Sandcastle, SHFB)
Reflector addin (More information)
Easy addin extensibility mechanism
SharpDevelop for Applications (SDA) allows you to host SharpDevelop in your applications (More information)
AvalonEdit WPF-based text editor is rehostable to add a programmer's editor to your applications (including code completion!)

Download it here, place it in your USB and you're ready:

http://www.icsharpcode.net/OpenSource/SD/Download/#SharpDevelop4x