Debian Packages (see below for source code tarballs)
 
A package may be available in your Linux repositories (and may be quite old). The newest versions are here. They might install on your flavor of Linux. If this fails, you can build from source code, as described below.
 
Warning for Ubuntu users: You should be able to click on the downloaded package file and the Ubuntu Software utility should start and install the package. However, this utility is buggy and does not always work. Sometimes it will install the Fotoxx package from the Ubuntu repositories instead of the downloaded package, while wrongly affirming that the downloaded package version is being installed. It is safer to avoid this utility and use the Debian utilities instead. If and when this problem is fixed, I will remove this notice.
$: sudo dpkg -r fotoxx                       ## remove the old package
$: sudo dpkg -i fotoxx-NN.N-x86_64.deb       ## install the new package
 
 
Packages for Ubuntu 16.04 
dkopp-6.9-x86_64.deb
Apr 01 2016
findwild-2.2-x86_64.deb Jan 03 2016
fotoxx-16.10.3-x86_64.deb
Oct 14 2016
fotoxx-16.11.1-x86_64.deb
Nov 16 2016
fotoxx-17.01.1-x86_64.deb
Jan 21 2017
fotoxx-maps-1.1-x86_64.deb Dec 01 2014  optional map files
galaxy2-1.1-x86_64.deb Jan 03 2016
lbench-3.2-x86_64.deb Dec 29 2016
mystuff-2.9-x86_64.deb May 28 2016
picpuz-2.7-x86_64.deb Jan 03 2016
sortpuz-1.4-x86_64.deb Jan 03 2016
ukopp-6.2-x86_64.deb Jan 08 2017
watsup-3.6-x86_64.deb May 31 2016
 
Packages for Ubuntu 16.10
dkopp-6.9-x86_64.deb
Apr 01 2016
findwild-2.2-x86_64.deb Jan 03 2016
fotoxx-16.10.3-x86_64.deb
Oct 14 2016
fotoxx-16.11.1-x86_64.deb Nov 16 2016
fotoxx-17.01.1-x86_64.deb
Jan 21 2017
fotoxx-maps-1.1-x86_64.deb Dec 01 2014  optional map files
galaxy2-1.1-x86_64.deb Jan 03 2016
lbench-3.2-x86_64.deb Dec 29 2016
mystuff-2.9-x86_64.deb May 28 2016
picpuz-2.7-x86_64.deb Jan 03 2016
sortpuz-1.4-x86_64.deb Jan 03 2016
ukopp-6.2-x86_64.deb Jan 08 2017
watsup-3.6-x86_64.deb May 31 2016
 
 
Source Code Tarballs
The following tar files contain a source program (C++), a build script (Make), 
and a user guide or man page. The installation procedure is explained below.
dkopp-6.9.tar.gz
Apr 01 2016
findwild-2.2.tar.gz Jan 03 2016
fotoxx-16.10.3.tar.gz
Oct 14 2016
fotoxx-16.11.1.tar.gz
Nov 16 2016
fotoxx-17.01.1.tar.gz
Jan 21 2017
fotoxx-maps-1.1.tar.gz Dec 01 2014  optional map files
galaxy2-1.1.tar.gz Jan 03 2016
lbench-3.2.tar.gz Dec 29 2016
mystuff-2.9.tar.gz May 28 2016
picpuz-2.7.tar.gz Jan 03 2016
sortpuz-1.4.tar.gz Jan 03 2016
ukopp-6.2.tar.gz Jan 08 2017
watsup-3.6.tar.gz May 31 2016
zfuncstest-6.5.tar.gz
Oct 01 2016

Dependencies:
The following packages are needed to build and install these programs: 
    libc6, xdg-utils,  g++,  libgtk-3.0-dev,  binutils
Fotoxx also needs: 
    libtiffxxx-dev,  libpngxxx-dev, liblcmsxxx-dev, libimage-exiftool-perl,
    librawxxx, libclutter-gtk-xxx, libchamplain-gtk-xxx-dev
    (xxx means whatever is available on your distro)

RPM names are different:
    For Fedora, Suse, and others using RPM, you will need to find the corresponding
    packages, which have different names from the above Debian/Ubuntu names.
  

Installation Procedure:
  0.  Install the above dependencies using your package manager.
  1.  Download the tar file (appname-xxx.tar.gz)
  2.  Open a terminal window and enter the following commands:
  3.  $ cd Downloads                       # go to the tar file
  4.  $ tar -xzf appname-xxx.tar.gz        # unpack the tar file
  5.  $ cd appname                         # go to unpacked files
  6.  $ make                               # build executable
  7.  $ sudo make install                  # install executable

Missing dependencies will cause error messages in step 6. 
Install these using your package manager and repeat step 6.
Step 7 installs the program files at  /usr/bin, /usr/share/appname, /usr/share/doc/appname


Uninstall appname:
  $ sudo rm -f /usr/bin/appname  
  $ sudo rm -R -f /usr/share/appname
  $ sudo rm -R -f /usr/share/doc/appname
  $ rm -R -f /home/<user>/.appname