I use Mac and Linux, and the only cross-platform solution I really like is HTML -- so I use Bluefish with local pages on Dropbox to generate and organize the material. For the formatted manuscript, I use LibreOffice.
I do like Scrivener on the Mac, and I do like Zim on Linux, but nothing is as seamless across platforms as HTML, and it's very flexible when it comes to organizing information and prose.
I do like Scrivener on the Mac, and I do like Zim on Linux, but nothing is as seamless across platforms as HTML, and it's very flexible when it comes to organizing information and prose.