> For the complete documentation index, see [llms.txt](https://doc.orbeon.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.orbeon.com/xforms/xbl/advanced-topics.md).

# Advanced topics

- [XBL Modes](https://doc.orbeon.com/xforms/xbl/advanced-topics/modes.md)
- [JavaScript companion classes](https://doc.orbeon.com/xforms/xbl/advanced-topics/javascript.md)
- [XBL library](https://doc.orbeon.com/xforms/xbl/advanced-topics/library.md)
- [Extensions](https://doc.orbeon.com/xforms/xbl/advanced-topics/extensions.md)
- [Attachment controls](https://doc.orbeon.com/xforms/xbl/advanced-topics/attachments.md)