Step 1: Install libary need
Open Terminal Command Line and type:
$ sudo apt-get install build-essential
$ sudo apt-get install xorg-dev
$ sudo apt-get install gcc
$ sudo apt-get install xlibs-dev
$ sudo apt-get install libxft-dev
If you can't install xorg-dev ; gcc ; xlibs-dev ; libxft-dev don't worry, at the Terminal, type:
$ sudo apt-get update
After finish, type:
$ sudo apt-get install build-essential
After update finish, type again
$ sudo apt-get install xorg-dev
$ sudo apt-get install gcc
$ sudo apt-get install xlibs-dev
$ sudo apt-get install libxft-dev
I'm sure 99% you can install, but somtime you can not do after try to fix like above, don,t worry, continue try this to fix
$ sudo apt-get clean
$ sudo apt-get update
$ sudo apt-get install build-essential

Step 2: Download and Install XVNKB 0.2.9a packageDownload xvnkb-0.2.9a.tar.bz2 packet. You can download from source anywhere if you find out it
$ wget http://xvnkb.sourceforge.net/xvnkb-0.2.9a.tar.bz2
Un-compress this packet
$ tar -xjvf xvnkb-0.2.9a.tar.bz2
Go to the folder after uncompress ( xvnkb-0.2.9a )
$ cd xvnkb-0.2.9a/
Type this command like
$ ./autogen.sh
$ ./configure
Open file config.h to change something inside
$ gedit config.h
After open, you will see like this
-e #ifndef __VK_CONFIG_H
#define __VK_CONFIG_H
#define VK_CHECK_SPELLING
#define VK_NEED_UCHAR
#define VK_NEED_USHORT
#define VK_NEED_UINT
#define VK_NEED_ULONG
#endif
Delete all and type this, then save
#define __VK_CONFIG_H
#define VK_CHECK_SPELLING
#define VK_USE_EXTSTROKE
#define VK_NEED_UCHAR
After finish, you type
$ make
$ sudo make install

Step 3: Install Unicode Fonts
$ sudo apt-get install msttcorefonts
FINISH INSTALLATION

Step 4: Run xvnkb program
In the Terminal, you can type
$ xvnkb
The symble ( logo ) will appear at right bottom screen. Default Initial is OFF, you can right click an chose option.
Thanks for your seeing.
P/S: Make xvnkb auto run when OS start
In the terminal, you type:
$ gnome-session-properties
After that, you chose NEW, in the NAME you will type what you want for easy remember this program, in the COMMAND you type xvnkb then chose OK then chose Close
Good Luck !

Hoặc có thể download bản dưới đây:
http://www.box.net/shared/dy9bolo0sk (Bản xvnkb dành cho Ubuntu 8.04)