UniKey is a very small, open-source utility that will allow you to type any text in the Vietnamese language using your Windows interface. UniKey will work with any Win32 platform - from Windows 9X to XP. It needs no installation and it is compatible with the three most popular input methods - TELEX, VNI and VIQR, which can be defined by the user.
UniKey supports many character sets and encodings, such as TCVN3 (ABC), VN Unicode, VIQR, VNI, VPS, VISCII, BK HCM1, BK HCM2, Vietware-X, Vietware-F, Unicode UTF-8, Unicode NCR Decimal/Hexadecimal, for Web editors. UniKey also supports smart typing as well as spelling checks.
The reduced number of screens needed to use UniKey are now available both in Vietnamese and in English. In the project page you can also find links to a number of Vietnamese fonts.
A library has been developed by a contributor that will help you integrate this software in Visual Basic applications (download link available at home URL). There is now also an open-source Linux and FreeBSD version available under the name of X-UniKey.