Atlassian products each define a set of plugin points, where plugins can add functionality. Each module type provides functionality to a different plugin point. For example, the event system will send events to all the modules of type 'Event Listener' in all the plugins loaded by Fisheye/Crucible.
Module Types Supported in Fisheye/Crucible
Downloadable Plugin Resources -- If your plugin requires Fisheye/Crucible to include additional static files such as images, you will need to use downloadable plugin resources to make them available.
Event Listener Module Type -- An event listener plugin module is an object which is notified when certain internal Crucible or Fisheye events occur.
Gadget Module Type -- A Gadget module allows Fisheye/Crucible to serve your gadget.xml file. See Gadget Development for more details on developing gadgets.
Gutter Renderer Module Type -- The Gutter Renderer plugin point allows you to display custom content in the margin of your source code view.
REST Module Type -- You can use the REST module type to expose services and data entities as REST APIs
SCM Module Type -- An SCM plugin module gives Crucible the ability to work with a custom version control system that is not supported out of the box.
Servlet Module Type -- Servlet plugin modules enable you to deploy Java servlets as a part of your plugins.
Spring Component Module Type -- Component plugin modules enable you to share Java components between other modules in your plugin and optionally with other plugins in the application.
Web Item Module Type -- Web UI plugin modules allow you to add links, tabs and sections of links to the Fisheye user interface. By adding a link to a servlet plugin, you can add your own pages to the UI.
Web Panel Module Type -- Web Panel plugin modules allow you to add a string of HTML to particular points in the Fisheye user interface. By including a link to a servlet plugin, you can add your own pages to the UI.
Web Resources -- If your plugin requires Fisheye/Crucible to include additional static Javascript or CSS files, you will need to use downloadable web resources to make them available.
Workflow Condition Module Type -- The Workflow Condition plugin point allows you to prevent review transition from happening depending on the conditions you've implemented.
Plugin Resources
If your plugins uses static content like images, Javascript or CSS, you make these available as resources.
Web Resources - Javascript and CSS files which are included in your page's <HEAD>.
Authentication Plugins
You can also write a plugin to allow Fisheye/Crucible to use other authentication methods. These do not use the Atlassian Plugins framework.
Writing Authentication Plugins.