public class <menu_name>
{
        public bool Init( Context in_context )
        {
                ...
        }
}

CStatus <menu_name>_Init( CRef& in_context )
{ 
        ... 
}

function <menu_name>_Init( in_context )
{ 
        ... 
}

def <menu_name>_Init( in_context ):
        ...

Function <menu_name>_Init( in_context )
        ...
End Function

sub <menu_name>_Init 
{ 
        my $in_context = shift; 
}

// JScript code generated by the Command Wizard
// Shows the Init callbacks for a command and for a menu
function XSILoadPlugin( in_reg )
{
 in_reg.Author = "sblair";
 in_reg.Name = "MyCommandPlugin";
 in_reg.Email = "";
 in_reg.URL = "";
 in_reg.Major = 1;
 in_reg.Minor = 0;

 in_reg.RegisterCommand("MyCommand","MyCommand");
 in_reg.RegisterMenu(siMenuTbGetPropertyID,"MyCommand_Menu",false,false);
 //RegistrationInsertionPoint - do not remove this line

 return true;
}

function XSIUnloadPlugin( in_reg )
{
 strPluginName = in_reg.Name;
 Application.LogMessage(strPluginName + " has been unloaded.");
 return true;
}

function MyCommand_Init( ctxt )
{
 var oCmd;
 oCmd = ctxt.Source;
 oCmd.Description = "";
 oCmd.ReturnValue = true;

 var oArgs;
 oArgs = oCmd.Arguments;
 oArgs.Add("Arg0",siArgumentInput);
 return true;
}

function MyCommand_Execute( Arg0 )
{

 Application.LogMessage("MyCommand_Execute called");
 // 
 // TODO: Put your command implementation here.
 // 
 return true;
}

function MyCommand_Menu_Init( ctxt )
{
 var oMenu;
 oMenu = ctxt.Source;
 oMenu.AddCommandItem("Run My Command","MyCommand");
 return true;
}

// C++ code generated by the Command Wizard
// Shows the Init callbacks for a command and a menu
#include <xsi_application.h>
#include <xsi_context.h>
#include <xsi_pluginregistrar.h>
#include <xsi_status.h>
#include <xsi_argument.h>
#include <xsi_command.h>
#include <xsi_menu.h>
using namespace XSI; 

SICALLBACK XSILoadPlugin( PluginRegistrar& in_reg )
{
 in_reg.PutAuthor(L"sblair");
 in_reg.PutName(L"My_CppCommandPlugin");
 in_reg.PutEmail(L"");
 in_reg.PutURL(L"");
 in_reg.PutVersion(1,0);
 in_reg.RegisterCommand(L"My_CppCommand",L"My_CppCommand1");
 in_reg.RegisterMenu(siMenuTbGetPropertyID,L"My_CppCommand_Menu",false,false);
 //RegistrationInsertionPoint - do not remove this line

 return CStatus::OK;
}

SICALLBACK XSIUnloadPlugin( const PluginRegistrar& in_reg )
{
 CString strPluginName = in_reg.GetName();
 Application().LogMessage(strPluginName + L" has been unloaded.");
 return CStatus::OK;
}

SICALLBACK My_CppCommand_Init( CRef& in_ctxt )
{
 Context ctxt( in_ctxt );
 Command oCmd;
 oCmd = ctxt.GetSource();
 oCmd.PutDescription(L"");
 oCmd.EnableReturnValue(true);

 ArgumentArray oArgs;
 oArgs = oCmd.GetArguments();
 oArgs.Add(L"Arg0");
 return CStatus::OK;
}

SICALLBACK My_CppCommand_Execute( CRef& in_ctxt )
{
 Context ctxt( in_ctxt );
 CValueArray args = ctxt.GetAttribute(L"Arguments");
 CValue Arg0 = args[0];

 Application().LogMessage(L"My_CppCommand_Execute called");
 // 
 // TODO: Put your command implementation here.
 // 
 // Return a value by setting this attribute:
 ctxt.PutAttribute( L"ReturnValue", true );

 // Return CStatus::Fail if you want to raise a script error
 return CStatus::OK;
}

SICALLBACK My_CppCommand_Menu_Init( CRef& in_ctxt )
{
 Context ctxt( in_ctxt );
 Menu oMenu;
 oMenu = ctxt.GetSource();
 MenuItem oNewItem;
 oMenu.AddCommandItem(L"My_CppCommand",L"My_CppCommand",oNewItem);
 return CStatus::OK;
}