Projeqtor is a web application.
You must install a web server with PHP and MySql.
You can do it easily with WAMP or EasyPHP.

You have to install it on a server.

If you just want to test this application in depth, or are the only person running it, there are application such as XAMPP that will create a local server with everything you need which is very simple.
1- Install XAMPP
2- Add decompressed file from ProjeQtOr to htdocs directory of XAMPP
3- Run XAMPP with Apache, MySQL and FIleZilla
4- Open localhost/projeqtor/

We recently posted a video showing how to install projeqtor
https://www.youtube.com/watch?v=7mXSqam5_nc
It is the frensh version,
we'll soon post the english version.