Coollector is currently available only in English, and only one instance of the program can run at the same time.
But you can have several coollections on the same computer...
When you launch the program, it loads the default coollection from the default location. But if you have other coollections somewhere, anywhere you want, you can launch them by double-clicking the coollection file.
http://www.coollector.com/help.html#coollection