Any Demos or Trial versions of Tools ?

Hi,

I’m in the process of finding a chess engine & interface that suits my chess interests.

I’d like to try out or evaluate a few before buying one.

I’ve tried out the 1 month demo of Shredder.

( in fact, although Shredder is clearly a power engine …

 I’m not impressed because if it’s lack of details in it’s user manual. The available information does not fully explain various features or details and it left me guessing about how to use some features )

I’d like to try out a few more before deciding which to buy

Can you point me towards any other that provide a demo / trial version /

Is there a demo version of Fritz ? or any other popular tools like Shredder / Fritz

Many Thanks