Set some environment variables in the file .profile (or .login, depending on your shell) in your home directory. Create the file if it is not there already.
QTDIR -- the directory in which you're building Qt
PATH -- to locate the moc program and other Qt tools
MANPATH -- to access the Qt man pages
LD_LIBRARY_PATH -- for the shared Qt library
This is done like this:
In .profile (if your shell is bash, ksh, zsh or sh), add the following lines:
QTDIR=/usr/local/qt
PATH=$QTDIR/bin

PATH
MANPATH=$QTDIR/man

MANPATH
LD_LIBRARY_PATH=$QTDIR/lib

LD_LIBRARY_PATH
export QTDIR PATH MANPATH LD_LIBRARY_PATH
In .login (in case your shell is csh or tcsh), add the following lines:
setenv QTDIR /usr/local/qt
setenv PATH $QTDIR/bin

PATH
setenv MANPATH $QTDIR/man

MANPATH
setenv LD_LIBRARY_PATH $QTDIR/lib

LD_LIBRARY_PATH
After you have done this, you will need to login again, or re-source the profile before continuing, so that at least $QTDIR is set. The installation will give an error message and not proceed otherwise.
On AIX set LIBPATH and on HP-UX set SHLIB_PATH instead of LD_LIBRARY_PATH.
Note that the SGI MIPSpro o32 and Sun WorkShop 5.0 targets are no longer supported as of Qt 3.3.
Install your license file as $HOME/.qt-license. For the free edition and evaluation version, you do not need a license file.
Compile the Qt library, and build the example programs, the tutorial and the tools (e.g. Qt Designer) as follows.
Type:
./configure
This will configure the Qt library for your machine. Note that GIF support is turned off by default. Run ./configure -help to get a list of configuration options. Read PLATFORMS for a list of supported platforms.
To create the library and compile all examples and the tutorial:
make
If you have problems, see
http://www.trolltech.com/platforms/.
In very few cases you may need to run /sbin/ldconfig or something similar at this point if you are using shared libraries.
If you have problems running the example programs, e.g. messages like
can't load library 'libqt.so.2'
you probably need to put a reference to the qt library in a configuration file and run /sbin/ldconfig as root on your system. And don't forget to set LD_LIBRARY_PATH as explained in 2) above.
The online HTML documentation is installed in /usr/local/qt/doc/html/ The main page is /usr/local/qt/doc/html/index.html. The man pages are installed in /usr/local/qt/doc/man/. The documentation is also accessible using Qt Assistant.
You're done. Qt is now installed.