I programmed apps for Nokia Symbian devices a lot, and it was amazing just how fast the OS was. Not the UI, mind you, Avkon was pretty slow, but the kernel. Lig

I programmed apps for Nokia Symbian devices a lot, and it was amazing just how fast the OS was. Not the UI, mind you, Avkon was pretty slow, but the kernel. Lightning fast. The Active Object model was a bit tricky to learn, but once you knew what you were doing, you had "light threads" (that were not really threads) caring about your network, audio etc. very, very efficiently. I was in awe of efficiency of the kernel. That said: * the learning curve was basically El Capitan of all learning curves, * the IDE called Carbide.c++ (a variant of Eclipse) sucked even more than regular Eclipse, * on-device debugging was horrible, barely there, * emulators were limited, a regular developer had no chance to debug many things such as audio or Bluetooth, * build toolchains were obsolete (imagine using GCC 2.x in 2011, with all its inefficiencies and bugs), * someone at Nokia decided that compatibility between devices did not matter and the Nokia world was so enormously fragmented (OS + UI) that releasing an application for all Nokias, even for all Nokias of one generation, was horrible, plus test devices were expensive. Symbian OS kernel would work just fine today. The rest of the ecosystem was rightly abandoned.