It is a Java software, which is supplied with a platform-specific installer for Windows or Mac OS X. To activate the printed in the CD jacket activation code is required. One can be downloaded from the Phase 6 website the latest version, instead of using the supplied CD.
The learning principle is quite simple: there are 6 card boxes. "Woken up" are words (ie enabled to learn from the word-stock), they end up in Cardfile 1. If you answer them in the query correctly, it is moved to file box 2, etc. If one makes a mistake, she wanders back to a box forward. The vocabulary in the front boxes are checked more frequently than in the rear boxes (because you already can better).
Words can be either self-type (either directly in the software, or such as an Excel list as a CSV file import), or you can buy one of the many offered finished vocabulary compilations of many publishers who offer their textbooks suitable vocabulary, sometimes even with Speech.
The great thing about Phase 6: there is the software not only as a paid PC / Mac program (Phase6 desktop), but also as an iOS and Android app, so you can also go at any time, can learn his vocabulary. About the paid Phase6-Cloud (9.99 EUR per year), all devices are synchronized with one another, so that you all have the same level of vocabulary and learning objects.
Too bad that the Klett Verlag offers only for his schoolbooks Phase6 vocabulary for sale. I attend an Italian course at the VHS. For the books of adult learning Velcro unfortunately offers no Phase6 vocabulary. But never mind: I have the vocabulary simply typed in an Excel spreadsheet and then imported into Phase6. You should use the correct character set when importing, so that special characters are displayed correctly.
The software may be installed according to Phase 6 support on up to 3 computers in the same household. For not another 20 EUR an absolutely fair and good offer. Really good!
Phase6 runs the way under Linux: just install Wine and then start the Windows installer using Wine. My daughter uses it on Ubuntu 13.04, I work under OS X 10.8 with Phase6 desktop.
The Phase6 desktop software supports multi-user operation: Multiple user accounts can be created. Each user has their own system settings, Phase6 cloud, etc., so you do not each other "in the enclosure" comes up.
From me an absolute buy recommendation!