A portable install mean you install Skychart on a removable media (USB stick) and you can plug it to any PC to run the application without any further configuration.

The example is given here for Windows but you can do almost the same on Linux, in this case use the tar installer.

The commands suppose your removable media is mounted on E: change accordingly if it use another letter.

This description use mostly a command line window for the clarity of the explanation but you can also use the equivalent graphical tool.
To open a command line window use the Start menu → Accessories → Command Prompt

1) Create a new folder on your removable media:

E:
mkdir portable_skychart
cd \portable_skychart

You need a specific program to extract the files from the Windows installer without to run it.
But if you have already installed the Skychart software at a version more recent than 3.7-2196 on a computer you can copy the folder “C:\Program Files\Ciel” to “E:\portable_skychart\skychart” and skip to step 8)

2) Get innounp from http://sourceforge.net/projects/innounp/files/ and put the file in E:\portable_skychart :

3) To extract the files use 7zip or the following command line:

unrar e innounp036.rar

4) Get CdC windows installer from http://ap-i.net/skychart
A portable install require a version more recent than 3.7-2196. Copy the file in E:\portable_skychart

5) Extract the CdC files without running the installer:

innounp.exe -x skychart-3.7-2196-windows.exe

6) Rename the application directory:

move {app} skychart

7) Delete the unneeded files:

del innounp036.rar  innounp.exe innounp.htm install_script.iss skychart-3.7-2196-windows.exe
rmdir /S {userappdata}

8) Create a folder for the program configuration:

cd \portable_skychart
mkdir userdata

9) If you not want to let any trace in the registry of the computer you need to inactivate the server functionality. Otherwise you can skip to step 10):

cd userdata
notepad skychart.ini

Type the following and save the file:

[main]
AutostartServer=0

10) Create a startup script:

cd \portable_skychart
notepad skychart.cmd

Type the following and save the file:

@ECHO off
set basedir=%CD%
start %basedir%\skychart\skychart.exe --config="%basedir%\userdata\skychart.ini" --userdir="%basedir%\userdata"

Now you can plug this USB stick on any (Windows) computer and run the program with a double click on skychart.cmd