The Malawian version "Bawo" doesn't seem to be very popular on the internet, there are only two rather unsatisfying posibilities to play Bawo on the computer. The Tanzanian version "Bao" is very similar though (see Rules) and there are two very good possibilities to play.

The only site to play Bawo online is a Open Source Project by Zombasoft. It is a rather simple Javascript-applet for the browser:
bawo.sourceforge.net

The second possibility to play Bawo on the computer is a DOS program that has been written in 1995. It offers the classic Bawo version (ten in the house) and also the Ntchuwa version (one in every front hole). Here are the instructions how to play it on modern computers:
Bawo and Ntchuwa DOS program (incl. DOS emulator)

The most fun is playing in real life! The International Bao Club wants to find Bao/Bawo players around the world and get them together to play. They also do tournaments in Europe. Once you subscribed there is a possibility to play Bao online against other members:
www.kibao.org

The best program to play Bao on the computer is probably www.baogame.com. You can play against the computer or against a second player on the same computer. You can even play against players on other computers via the chat function:
www.baogame.com