1. You will receive all Professional Edition versions 2.x and 3.x including version 4.0 immediately after they are released.
2. If you buy a subscription for Strawberry Prolog then you will have the possibility to buy together with it 200 shares from Strawberry Prolog at 50 cents per share (look at Shares and Source).
3. You obtain technical support by e-mail and we will try to remove immediately all the problems in the compiler that hamper your work.
4. You will help for development of Strawberry Prolog.
We admire any help. You can help with money by buying of shares or with
ideas and bug reports. Also you can help by creating of powerful programs
on Strawberry Prolog platform. You can take the source code of Strawberry
Prolog and to make your own improvements on it.