Sailfish OS is being ported to many platforms already in the open source community. We are active participants in the community development and we'll do our best to make it flourish for all interested Sailfish users. We encourage to follow this development closely.
Specifically Nemo Mobile has a UI and a set of applications that we won't use in the final Jolla product nor in Sailfish OS. We are contributing to Nemo Mobile and our intention is to keep Sailfish OS compatible with Nemo Mobile and vice versa.
Qt APIs (QtQuick, QtMobility, QtWebkit and more) should be used by typical Sailfish OS applications. Also standard Linux APIs within reason for mobile usage will be available.
Yes Sailfish SDK is based on QtCreator and will be available in Windows, Linux and OSX.
Sailfish runs on the Jolla phone.
Sailfish has also been ported to devices like:
Acer Iconia Tab W500
Google Nexus One
Google Nexus 4
Google Nexus 5
Google Nexus 7
Samsung Galaxy S3
PackardBell Butterfly Touch
Nokia N950 and Nokia N9 - during several presentations given by Jolla
Sailfish will be able to run most applications that were originally developed for MeeGo and Android, in addition to native Sailfish applications. This will give it a large catalogue of available apps on launch.
Considering upon Jolla's declarations that Sailfish OS is be able to use software from following platforms
Sailfish (natively created + ported like from Qt, Symbian, MeeGo - developers have reported that porting a Qt written software with Sailfish SDK takes a few hours only)
Android applications are directly running in Sailfish OS. They are compatible as they are in third-party Android stores, with no needed modification (in most cases).
MeeGo (because of backward compatibility thanks to MeeGo code legacy included in the Mer core)
Unix and Linux (as Sailfish is Linux then using such a software is possible, especially RPM packages, either in terminal/console mode or with limitations implying from using Sailfish UI, if not ported and adjusted)
Jolla has revealed its plans to use the following technologies in Sailfish OS:
The Mer software distribution core
A custom built user interface
QML and Qt
Sailfish is a Linux-based mobile operating system developed by Jolla in cooperation with the Mer project and supported by the Sailfish Alliance. It is to be used in upcoming smartphones by Jolla and other licencees. Although it is primarily targeted at mobile phones, it is also intended to support other categories of devices.