CPSInstaller provides CMF products authors with an extensible framework to help them writing installers: scripts that set up products for use in the CMF, including boring tasks such as registering or configuring skins, portal types, actions, catalog indexes, permissions, schemas, widgets, layouts, vocabularies, translations, events...
CPSInstaller will be the standard way to install products in CPS 3.1, and extends and supersedes the old CPS 3.0 installer which was located in the CPSDefault product (CPSDefault.Installer). By removing the dependency on CPSDefault, we expect that it will make it easier to install CPS products (CPSDocument, CPSSchemas, CPSDirectory...) on CMF sites (including Plone sites) that don't include CPSDefault, and to write non-CPS products installers that will make them easy to install on CPS sites.
The cps-devel mailing list is the place for support and discussions about future functionalities of CPSInstaller.