FLTK/Downloading and installing

Downloading FLTK
Go to FLTK's software page and click on the latest FLTK 2.0 package. Choose the compression you're able to decompress (bzip2 or gzip) and click on the nearest mirror. Sometimes the mirrors are not up to date, then try another one or pick an older package. Don't use the SourceForge.net project page, it's deprecated.

Linux
Decompressing the bzip2 archive: tar jxf fltk-2.0.x-rNNNN.tar.bz2

Decompressing the gzip archive: tar zxf fltk-2.0.x-rNNNN.tar.gz

To build the framework, launch the configuration script and type make: ./configure make

If everything built fine (no error message), install it: sudo make install

You're ready to write FLTK 2 applications!