Re: Move on and let it die
iOS and Android are what they are, bloated macro kernel OS based on UNIX/Linux concepts. iOS & Android developers are not going to scrape the core of the OS and re-write it from scratch. That though is the only way to get an efficient, secure, low power, reliable and low footprint OS.
Symbian was developed from a OS especially designed from ground up for a single user running multiple small applications in tiny memory on battery powered cpu.
UNIX was designed for mains powered Mini-computers and multiple users. Linux was designed as a functional clone for the 386 CPU with disk storage. It's only because a mobile phone is more powerful and more storage than a 2001 Laptop that iOS or Android is practical at all.
Symbian OS developers are going to want to work on ARM embedded systems, not iOS and Android phones.
Symbian *was* open source for a while. How they get the genie back in the bottle? An embedded controller or other application using a Raspberry Pi needs none of GUI junk that Nokia built on top of Symbian. If you DON'T have screen on the Pi, then VXworks, QNX, or Symbian may make more sense than Llinux which needs a hacked kernel to be "real time". Set-boxes, TVs, WiFi points and Routers can cheerfully use vanilla Linux as there are no "Real Time" constraints or "deterministic at compile time" requirements.