Start by installing the default Orbix 6.3.5 Windows kit (i.e. the one which supports VC6.0, VC7.1 and VC8.0).

Adding VC9.0 kit:

After installing the default Orbix 6.3.5 Windows kit, create the following two directories: 
    %IT_PRODUCT_DIR%\\asp\\6.3\\include\\vc90
    %IT_PRODUCT_DIR%\\asp\\6.3\\lib\\vc90

From the Orbix 6.3.5 Windows 32-bit VC9.0 installation, copy the following files:

Source from VC9.0 installation           Destination in VC6.0/7.1/8.0 installation
bin\\ *.dll *.dps                                   bin\\
bin\\windows\\ *.dll                              bin\\windows\\
bin\\windows\\checked\\ *.dll                bin\\windows\\checked\\
asp\\6.3\\lib\\ *.lib                                 asp\\6.3\\lib\\vc90\\
asp\\6.3\\include\\ *                              asp\\6.3\\include\\vc90\\
asp\\6.3\\demos\\demo_vc90_32.mk    asp\\6.3\\demos\\

Finally the following file bin\\it_java_server_terminator5.dll should not be overwritten in the kit. A different version resides in the VC9.0 kit, so ensure the base version is kept.

For the demos the demos_vc90_32.mk will need to change the variables:

ART_CXX_INCLUDE_DIR=  "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\include"
ART_LIB_DIR=                    "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\lib"
to
ART_CXX_INCLUDE_DIR=  "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\include\\vc90"
ART_LIB_DIR=                    "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\lib\\vc90"

Adding VC10.0 kit:

Create the following two directories in the merged kit:
    %IT_PRODUCT_DIR%\\asp\\6.3\\include\\vc100
    %IT_PRODUCT_DIR%\\asp\\6.3\\lib\\vc100

From your Orbix 6.3.5 Windows 32-bit VC10.0 installation, copy the following files:

Source from VC10.0 installation            Destination in VC6.0/7.1/8.0/9.0 installation
bin\\ *.dll *.dps                                       bin\\
bin\\windows\\ *.dll                                  bin\\windows\\
bin\\windows\\checked\\ *.dll                    bin\\windows\\checked\\
asp\\6.3\\lib\\ *.lib                                     asp\\6.3\\lib\\vc100\\
asp\\6.3\\include\\ *           .;                       asp\\6.3\\include\\vc100\\
asp\\6.3\\demos\\demo_vc100_32.mk      asp\\6.3\\demos\\

Finally the following file bin\\it_java_server_terminator5.dll should not be overwritten in the kit. A different version resides in the VC10.0 kit, so ensure the base version is kept.

For the demos the demos_vc100_32.mk will need to change the variables:

ART_CXX_INCLUDE_DIR=  "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\include"
ART_LIB_DIR=                    "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\lib"
to
ART_CXX_INCLUDE_DIR=  "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\include\\vc100"
ART_LIB_DIR=                    "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\lib\\vc100"

Finally the following file bin\\it_java_server_terminator5.dll should not be overwritten in the kit. A different version resides in the VC10.0 kit, so ensure the base version is kept.

For the demos the demos_vc100_32.mk will need to change the variables:

ART_CXX_INCLUDE_DIR=  "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\include"
ART_LIB_DIR=                    "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\lib"
to
ART_CXX_INCLUDE_DIR=  "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\include\\vc100"
ART_LIB_DIR=                    "$(IT_PRODUCT_DIR)\\asp\\$(IT_PRODUCT_VER)\\lib\\vc100"