iOS, Android, Tizen, Ubuntu Touch, Firefox OS... Seems like perhaps a lot of people are trying to get VC funding on the back of iOS success, no?
FirefoxOS, Mozilla's, no VC funding.
Ubuntu, Canonical is funded by Shuttleworth.
Android was a startup once upon a time before Google bought it, but that was before iOS was out.
The only actual VC-funded entry is the one you omit, Jolla.