# Advanced resource concepts

In Resources overview we took a look at the basic services and APIs provided by the `org.eclipse.core.resources` plug-in. This and other related plug-ins also contain many advanced features that are useful for plug-ins that require a deeper level of integration. For details on these advanced features, take a gander at some of these topics:

- Project natures
- Incremental project builders
- Derived resources
- Workspace save participation
- Resource modification hooks
- Refresh providers
- Alternate file systems
  - Using the file system API
  - Working with resources in other file systems
  - File system providers
  - User interface support for alternative file systems