[SkyMarshal]

Tomboy [1] + webnotes [2] with the notes folder automatically synced to Dropbox/SpiderOak/etc. Or Vim + VimOrganizer/vim-orgmode.

[1]: https://wiki.gnome.org/Apps/Tomboy

[2]: https://itunes.apple.com/us/app/webnotes-powered-by-ubuntu/i...

[3]: http://lifehacker.com/5839633/tomboy-is-a-free-lightweight-n...