Features of ACS included a core set of APIs, datamodels, and database routines for coordinating information common to all community web applications, as well as modules such as workflow management, CMS, messaging, bug/issue tracking, project tracking, e-commerce, and bboards.

ACS was built in the mid-1990s to support the photo.net online community as well as a variety of Internet services from Hearst Corporation.

[1] The initial developers included Tracy Adams, Ben Adida, Eve Andersson, Jin S. Choi, Philip Greenspun, Aurelius Prochazka, and Brian Tivol.

[citation needed] The Open Architecture Community System provides: OpenACS runs on AOLserver and NaviServer with either Oracle or PostgreSQL as its database.

[citation needed] Projects that were or are based on OpenACS include dotLrn, dotFolio, dotCommunity, dotConsult, Project-Open, and Voice Online Communities.