Note that python-stem appears in Debian wheezy and newer (so by extension Tails 1.1 and newer), and it appears in Ubuntu 13.10 and newer. Older versions of Debian and Ubuntu aren't supported.
To install the right dependencies, you need homebrew and pip installed on your Mac. Follow instructions at http://brew.sh/ to install homebrew, and run `sudo easy_install pip` to install pip.
* Download and install the latest python 2.7 from https://www.python.org/downloads/ -- make sure you install the 32-bit version.
* Right click on Computer, go to Properties. Click "Advanced system settings". Click Environment Variables. Under "System variables" double-click on Path to edit it. Add `;C:\Python27;C:\Python27\Scripts` to the end. Now you can just type `python` to run python scripts in the command prompt.
* Go to https://pip.pypa.io/en/latest/installing.html. Right-click on `get-pip.py` and Save Link As, and save it to your home folder.
* Open `cmd.exe` as an administrator. Type: `python get-pip.py`. Now you can use `pip` to install packages.
* Go to http://www.riverbankcomputing.com/software/pyqt/download and download the latest PyQt4 for Windows for python 2.7, 32-bit (I downloaded `PyQt4-4.11-gpl-Py2.7-Qt4.8.6-x32.exe`), then install it.
* Go to http://sourceforge.net/projects/pywin32/ and download and install the latest 32-bit pywin32 binary for python 2.7. I downloaded `pywin32-219.win32-py2.7.exe`.
* Go to http://nsis.sourceforge.net/Download and download the latest NSIS. I downloaded `nsis-3.0b0-setup.exe`.
* Right click on Computer, go to Properties. Click "Advanced system settings". Click Environment Variables. Under "System variables" double-click on Path to edit it. Add `;C:\Program Files (x86)\NSIS` to the end. Now you can just type `makensisw [script]` to build an installer.
* Go to http://msdn.microsoft.com/en-us/vstudio/aa496123 and install the latest .NET Framework. I installed `.NET Framework 4.5.1`.
* Go to http://www.microsoft.com/en-us/download/confirmation.aspx?id=8279 and install the Windows SDK.
* Right click on Computer, go to Properties. Click "Advanced system settings". Click Environment Variables. Under "System variables" double-click on Path to edit it. Add `;C:\Program Files\Microsoft SDKs\Windows\v7.1\Bin` to the end.
* You'll also, of course, need a code signing certificate. I roughly followed [this guide](http://blog.assarbad.net/20110513/startssl-code-signing-certificate/) to make one using my StartSSL account.
* Once you get a code signing key and certificate and covert it to a pfx file, import it into your certificate store.
* Open a command prompt, cd into the onionshare directory, and type: `pyinstaller -y install\onionshare-win.spec`. Inside the `dist` folder there will be a folder called `onionshare` with `onionshare.exe` in it.
Note that you must have a code signing certificate installed in order to use the `install\build_exe.bat` script, because it tries code signing both `onionshare.exe` and `OnionShare_Setup.exe`.