OpenACS (Open Architecture Community System) is an advanced toolkit for building scalable, community-oriented web applications. If you're thinking of building an enterprise-level web application, OpenACS is a solid, proven foundation that will give you a 3-6 month headstart.
OpenACS is also a collection of pre-built applications and services that you can use to build your web site/application. Through a modular architecture, OpenACS has packages for user/groups management, content management, e-commerce, news, FAQ, calendar, forums, bug tracking, full-text searching, and much more.
OpenACS relies on AOLserver, the free, multithreaded, scalable, Tcl-enabled, web/application server used by America On-Line for most of its web sites, and a true acid-compliant Relational Database Management System (RDBMS). Currently OpenACS supports PostgreSQL, an open source RDBMS, and Oracle. (read more)
The OpenACS toolkit is based on the ArsDigita Community System. ArsDigita (now part of Red Hat, Inc.) kindly made their work available under the GPL, making all of this possible.
“The ArsDigita Community System (ACS) is a toolkit of software that will help you build Web services with a collaborative dimension, ranging from knowledge management within companies to B2C ecommerce to product support and community among the customers. The software is free and open-source and has been tested in heavy use since 1995.” - Philip Greenspun
OpenACS was born when Don Baccus, Ben Adida, et al decided to port ACS from Oracle to PostgreSQL, thus making it a fully open-source solution.
OpenACS 4.7.0d is the next generation of the web toolkit. It's based on ACS 4, but no longer follows ArsDigita development. Unlike ACS (which required Oracle) and OpenACS 3.x (which required PostgreSQL), OpenACS 4.7.0d allows you to use either database. It's also built in such a way to allow enterprising hackers (in the good sense of the word) to extend it to other databases. Don Baccus leads the development and numerous developers and non-developers contribute from around the world.
The OpenACS community would like to hear your comments and help you in your endeavors with the system. Stop by our web site and feel free to ask a question, post ideas or whatever.