Project X₂7 - an import translator for Final Cut Pro 7 - translates the brand new Final Cut Pro X Project XML (fcpxml) and converts it for import into Final Cut Pro 7. Your Final Cut Pro X Project becomes a Final Cut Pro 7 Sequence, in a new or existing project.
Project X₂7 (Project 10 to 7) allows you to take your Final Cut Pro X timeline (Project) to Final Cut Pro 7, Color, Adobe Premiere Pro (and then via dynamic link to After Effects) or other Final Cut Pro 7 XML workflow tools.
Via Final Cut Pro 7 you can also link to Soundtrack Pro (sadly Soundtrack Pro's project format has never been published), to Motion 4, or to OMF output for ProTools.
Via Nicolas Weil