推荐几个和stackoverflow类似的开源框架，PostgreSQL重度用户建议使用OSQA，可以支持问题，回答，comment的中文全文检索。
List of the open source Q&A implementation or stackoverflow-like website, with “Active” development and promising features and community.
P.S This list is not in any particular order.
1. OSQA
- Website : http://www.osqa.net
- Demo : http://meta.osqa.net
- Language : Python, Django
- Database : MySQL, PostgreSQL or Microsoft SQL Server
- License : GNU General Public Licence (GPL)
- Source code : http://www.osqa.net/download/
- Created by : Folks at DZone
2. Shapado
- Website : http://shapado.com
- Demo : http://shapado.com
- Language : Ruby , MongoMapper
- Database : MongoDB (Document Based DB engine)
- License : GNU Affero General Public License (AGPL)
- Source code : http://gitorious.org/shapado
- Created by : David A. Cuadrado
3. Askbot
- Website : http://askbot.org
- Demo : http://askbot.org
- Language : Python, Django
- Database : MySQL, PostgreSQL
- License : GPL3
- Source code : https://github.com/ASKBOT/askbot-devel/
- Created by : Mike Chen and Sailing Cai
4. Question2Answer
- Website : http://www.question2answer.org
- Demo : http://www.question2answer.org/qa/
- Language : PHP
- Database : MySQL
- License : GNU General Public Licence (GPL)
- Source code : http://www.question2answer.org/install.php
- Created by : Gideon Greenspan
5. LampCMS
- Website : http://www.lampcms.com
- Demo : http://support.lampcms.com
- Language : PHP
- Database : MongoDB
- License : GNU LESSER GENERAL PUBLIC LICENSE (LGPL) version 3
- Source code : https://github.com/snytkine/LampCMS
- Created by : Dmitri Snytkine (Twitter)