The current version is ready for Trac 1.0.x and 0.12.x
This plugin alters Trac's behavior so that the interface supports multiple layers of types. In project with lots of types, rearranging these types into several layers can clear up the list of tickets and subtickets.
The plugin does not change the data model of the ticket; it merely manipulates the user interface. So a typo task with the subtickettype development and release will be stored in the database as task/development and task/release.
To install the module see the TracPlugins page on http://trac.edgewall.org/wiki/TracPlugins. After activating the plugin in the configuration file or through the plugins page, it will be activated without any further configuration.
To create types with subtickettypes, then you have to add these using the standard type admin page. If you enter the following ticket types:
tasktask/developmenttask/release
Then the user interface will show the development and release as a subtickettypes of the task type.
You can get help on the plugin by visitng Freenode #pyramid channel and pinging goodwill.
This plugin was based heavily on subcomponents plugin by "Niels Sascha Reedijk" located here: http://hg.haiku-os.org/trac-subcomponent, http://trac-hacks.org/wiki/SubcomponentsPlugin