diff --git a/src/VisVim/DSAddIn.cpp b/src/VisVim/DSAddIn.cpp
new file mode 100644
index 0000000..3e72544
--- /dev/null
+++ b/src/VisVim/DSAddIn.cpp
@@ -0,0 +1,160 @@
+#include "stdafx.h"
+#include "VisVim.h"
+#include "DSAddIn.h"
+#include "Commands.h"
+
+#ifdef _DEBUG
+#define new DEBUG_NEW
+#undef THIS_FILE
+static char THIS_FILE[] = __FILE__;
+
+#endif
+
+// This is called when the user first loads the add-in, and on start-up
+//  of each subsequent Developer Studio session
+STDMETHODIMP CDSAddIn::OnConnection (IApplication * pApp, VARIANT_BOOL bFirstTime,
+				     long dwCookie, VARIANT_BOOL * OnConnection)
+{
+	AFX_MANAGE_STATE (AfxGetStaticModuleState ());
+	*OnConnection = VARIANT_FALSE;
+
+	// Store info passed to us
+	IApplication *pApplication = NULL;
+	HRESULT hr;
+
+	hr = pApp->QueryInterface (IID_IApplication, (void **) &pApplication);
+	if (FAILED (hr))
+	{
+		ReportLastError (hr);
+		return E_UNEXPECTED;
+	}
+	if (pApplication == NULL)
+	{
+		ReportInternalError ("IApplication::QueryInterface");
+		return E_UNEXPECTED;
+	}
+
+	m_dwCookie = dwCookie;
+
+	// Create command dispatch, send info back to DevStudio
+	CCommandsObj::CreateInstance (&m_pCommands);
+	if (! m_pCommands)
+	{
+		ReportInternalError ("CCommandsObj::CreateInstance");
+		return E_UNEXPECTED;
+	}
+	m_pCommands->AddRef ();
+
+	// The QueryInterface above AddRef'd the Application object.  It will
+	// be Release'd in CCommand's destructor.
+	m_pCommands->SetApplicationObject (pApplication);
+
+	hr = pApplication->SetAddInInfo ((long) AfxGetInstanceHandle (),
+		(LPDISPATCH) m_pCommands, IDR_TOOLBAR_MEDIUM, IDR_TOOLBAR_LARGE,
+		m_dwCookie);
+	if (FAILED (hr))
+	{
+		ReportLastError (hr);
+		return E_UNEXPECTED;
+	}
+
+	// Inform DevStudio of the commands we implement
+	if (! AddCommand (pApplication, "VisVimDialog", "VisVimDialogCmd",
+			  IDS_CMD_DIALOG, 0, bFirstTime))
+		return E_UNEXPECTED;
+	if (! AddCommand (pApplication, "VisVimEnable", "VisVimEnableCmd",
+			  IDS_CMD_ENABLE, 1, bFirstTime))
+		return E_UNEXPECTED;
+	if (! AddCommand (pApplication, "VisVimDisable", "VisVimDisableCmd",
+			  IDS_CMD_DISABLE, 2, bFirstTime))
+		return E_UNEXPECTED;
+	if (! AddCommand (pApplication, "VisVimToggle", "VisVimToggleCmd",
+			  IDS_CMD_TOGGLE, 3, bFirstTime))
+		return E_UNEXPECTED;
+	if (! AddCommand (pApplication, "VisVimLoad", "VisVimLoadCmd",
+			  IDS_CMD_LOAD, 4, bFirstTime))
+		return E_UNEXPECTED;
+
+	*OnConnection = VARIANT_TRUE;
+	return S_OK;
+}
+
+// This is called on shut-down, and also when the user unloads the add-in
+STDMETHODIMP CDSAddIn::OnDisconnection (VARIANT_BOOL bLastTime)
+{
+	AFX_MANAGE_STATE (AfxGetStaticModuleState ());
+
+	m_pCommands->UnadviseFromEvents ();
+	m_pCommands->Release ();
+	m_pCommands = NULL;
+
+	return S_OK;
+}
+
+// Add a command to DevStudio
+// Creates a toolbar button for the command also.
+// 'MethodName' is the name of the methode specified in the .odl file
+// 'StrResId' the resource id of the descriptive string
+// 'GlyphIndex' the image index into the command buttons bitmap
+// Return true on success
+//
+bool CDSAddIn::AddCommand (IApplication* pApp, char* MethodName, char* CmdName,
+			   UINT StrResId, UINT GlyphIndex, VARIANT_BOOL bFirstTime)
+{
+	CString CmdString;
+	CString CmdText;
+
+	CmdText.LoadString (StrResId);
+	CmdString = CmdName;
+	CmdString += CmdText;
+
+	CComBSTR bszCmdString (CmdString);
+	CComBSTR bszMethod (MethodName);
+	CComBSTR bszCmdName (CmdName);
+
+	// (see stdafx.h for the definition of VERIFY_OK)
+
+	VARIANT_BOOL bRet;
+	VERIFY_OK (pApp->AddCommand (bszCmdString, bszMethod, GlyphIndex,
+				     m_dwCookie, &bRet));
+	if (bRet == VARIANT_FALSE)
+	{
+		// AddCommand failed because a command with this name already exists.
+		ReportInternalError ("IApplication::AddCommand");
+		return FALSE;
+	}
+
+	// Add toolbar buttons only if this is the first time the add-in
+	// is being loaded.  Toolbar buttons are automatically remembered
+	// by Developer Studio from session to session, so we should only
+	// add the toolbar buttons once.
+	if (bFirstTime == VARIANT_TRUE)
+		VERIFY_OK (pApp->AddCommandBarButton (dsGlyph, bszCmdName, m_dwCookie));
+
+	return TRUE;
+}
+
+void ReportLastError (HRESULT Err)
+{
+	char *Buf = NULL;
+	char Msg[512];
+
+	FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER,
+		       NULL, Err,
+		       MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
+		       Buf, 400, NULL);
+	sprintf (Msg, "Unexpected error (Error code: %lx)\n%s", Err, Buf);
+
+	::MessageBox (NULL, Msg, "VisVim", MB_OK | MB_ICONSTOP);
+	if (Buf)
+		LocalFree (Buf);
+}
+
+void ReportInternalError (char* Fct)
+{
+	char Msg[512];
+
+	sprintf (Msg, "Unexpected error\n%s failed", Fct);
+	::MessageBox (NULL, Msg, "VisVim", MB_OK | MB_ICONSTOP);
+}
+