JBoss Tools introduced JSF 2 Composite Component support in version 3.2.0.M1, it matured through several development versions and got a lot of useful features:
- Content assist for component developers
- Content assist for component users
- Validation and quick fixes
- Rendering in XHTML Visual Editor
- Resource Navigation in source and visual part of XHTML Visual Editor
Read full article about JBoss Tools JSF 2 Composite Component Support.