Besides shapado which other Q&A Open Source Projects excist and how to they compare?

http://osqa.net/ – OSQA is an Open Source Q&A System written using Django. Users can ask and answer questions, comment and vote for the questions of others and their answers. Both questions and answers can be revised and improved. Questions can be tagged with the relevant keywords to simplify future access and organize the accumulated material. OSQA can be downloaded from the project’s GitHub repository at http://github.com/rickross/osqa. It is under GNU General Public License.

http://qhub.com/ – Qhub is a simple way to create a Q&A website. While other Q&A websites are great for information sharing and communities, Qhub offers a more targeted community managed by the people that are interested in that particular subject area.

Each group is set up and started by an owner. Friends, colleagues, club members and more are invited to join and the questions can begin. Qhub offers the ability to customize each site. There is full management of your site, its members and content. It also offers the ability to use your own domain name.

If someone asking you a question and you have the answer, why not open up that knowledge to the web community for their and your benefit?

Liam