We don't have many open-source options in the mobile phone world:

Android - False open-source as @EJ pointed out earlier
Samsung's Tizen  - Likely the same as Android
SailfishOS - Based on the fantastic open-source Mer project, but the UI is proprietary
Ubuntu Touch - Looks promising, but they still haven't shown anything that works properly even on supported phones

That leaves us with FirefoxOS, which is limited to just web apps.

That's why we're asking Nokia/Microsoft to release the source code to the rock solid Symbian operating system.

It makes sense for them to do this because:
1) It would get them major points with open-source fans and
2) They have no use for it anymore because they only make Windows Phones now.

So please sign this petition to save the mobile phone industry
http://www.change.org/petitions/nokia-corporation-microsoft-corporation-release-symbian-source-code-make-it-open-source-release-latest-update-builds-save-the-environment#share

singed

Interesting phone: the ZTE Open


An open-source phone by the one company that would never scroogle you.

Only $80 unlocked
http://www.ebay.com/itm/like/281165818989?lpid=82

Looks like an interesting target for Pocket Rigs. Less crowded app store meaning less competition.
Like a big fish in a small pond....