Updated version available through project wiki

Prerequisites

Python
wxPython
SciPy
PyMOL

You may also want to get HBPLUS. It appears to be currently bundled with LIGPLOT (excellent program to generate interaction diagrams), which you can get here.

For Ubuntu/Debian users, the following should work to get wxPython, scipy and yes, PyMOL (you have python installed by default):
sudo apt-get install python-wxgtk2.8
sudo apt-get install python-scipy
sudo apt-get install pymol

Download HydroBonNet

The latest version is available here.

Linux

Create temporary folder, move the downloaded tarball into it, untar and change to the newly created folder, e.g.
mkdir tmp
cd tmp
mv ~/Downloads/hydrobonnet-0.0.1-Volokolamsk.tar.gz .
tar xvzf hydrobonnet-0.0.1-Volokolamsk.tar.gz
cd hydrobonnet-0.0.1-Volokolamsk
Now build the package for your distro.
./setup.py build
The installation itself requires admin privileges. Specific commands depend on Linux distro as well as your personal preferences. You can always just switch to root account. In Ubuntu
sudo ./setup.py install
And to clean up
cd ../../
rm -fr tmp
This is it! Just type "hybonet" in the command line and hit enter.

Install without admin privileges

If you don't have administrative privileges, donwload the "notroot" tarball (e.g. hydrobonnet-0.0.1-Volokolamsk-notroot.tar.gz). Untar it as above somewhere, this will create the same folder. However, it will not contain the setup.py script, but the "hybonet" executable instead. Just change working directory to that folder and execute it. Alternatively, you can create an alias, e.g. add this to your ~/.bashrc file
alias hybonet='/home/sware/hydrobonnet-0.0.1-Volokolamsk/hybonet'
Of course, the disadvantage here is that software will not become automatically available to other users of the workstation until they set up the same alias. And the caveat remains that you have to have all the prerequisites, but you only need to ask your system administrator to install it and then you can keep updating HydroBonNet on your own.

Mac OSX

The above Linux installation procedure should work. If it doesn't, I can't really help you much as I don't own (and have no plans to own) any iDevice. Naturally, this shows my lack of good taste, as there is nothing more beautiful than a white computer adorned with a fruit logo.

Microsoft Windows

Having even less patience for wavy squares, I can only say that I have no idea if the windows binaries I provide actually work. They are not tested on a reqular basis, so please report any problems you might have and I'll give it my best effort. Which may be about as much effort as the wavy square company makes to ensure that my son can play XP-compatible games under Vista. My apologies.