The Windows version runs fine in WINE, alternatively they offer a very cut-down web-based solution called 1Password Anywhere (which I use on my Chromebook).
(There's an official Android client too, which wasn't mentioned above)
The only way to get some (read-only) support in Linux is by syncing the 1Password folder with Dropbox (last time I tried it did not work locally). If you open the webpage that is in that folder via Dropbox, you can log-in and read password.
