Getting Started With OpenACS
Although this Oracle-based toolkit is Open Source and free, Oracle itself is prohibitively expensive for people who want to deploy sophisticated, low-cost Web sites. PostgreSQL is a widely available Open Source RDBMS that has greatly improved in quality in the past two years. In early 2000, a small group of software developers familiar with the ACS decided to port it to PostgreSQL; on May 1, 2000, the developers released the first version of OpenACS.
The toolkit runs under AOLserver, an extremely efficient, threaded, and reliable Open Source Web server that runs some of the busiest Web sites in the world. AOLserver offers an RDBMS-independent API with persistent, pooled database connections and an internal Tcl interpreter that efficiently executes dynamic scripts. AOLserver's ADP pages allow the programmer to insert snippets of Tcl directly into HTML pages.