Qt source code and information

Qt source code is not modified and can be downloaded here.

Linux: packages don't contain Qt libraries, the executable is dynamically linked
with distribution's Qt4 libraries and will work with any proper
Qt4 installation (recommended 4.8).
Windows: the executable is dynamically linked with unmodified Qt 5.4.2 libraries
and will work with any proper Qt5 installation.
Newer versions of Qt5 libraries can be used.