Most upgrades for OpenACS are quite straightforward. See the upgrades section of the docs for information on how to upgrade. The basic idea is that you upgrade the files, and then upgrade the database as well.

There were some upgrades that historically were more difficult.

• Upgrading from ACS to OpenACS
• [Upgrading 4.6.3 to 5.0.x] see: http://openacs.org/doc/current/upgrade-4.6.3-to-5.html

      also most recent versions of upgrade software in cvs head: http://cvs.openacs.org/cvs/openacs-4/contrib/misc/

• Other documented upgrades at: http://openacs.org/doc/current/upgrade.html