NEIL_M  It will have to get better before it beats RarMe and UnRaR X - both free.

Decompress - free - http://www.macupdate.com/info.php/id/9365/unrarx

Uncompress - free - http://www.macupdate.com/info.php/id/12598/rarme  
(Version 1.0.2)

MAXTER  The Demo Period is ridiculously short  
(Version 1.0)

BEAMY  Hopefully this explanation is better and works for everyone.

Step by step guide (don't do anything else in addition) :

1. start the program

2. click "Later" or "Never" in the "Do you want to install the Finder plug-in ?" window.

3. click "Cancel" in the "Please buy" window

4. click the little "Gear" symbol in the main window

(info: after clicking the "Gear" symbol 2 options appear: "Use password" and "Create parts ..." DON'T tick them, leave them alone)

5. go to the "RarMachine" menu and choose "Preferences"

--> NilObjectException error window appears

*****

(I use MacOS 10.4.11 intel)

When you start the program there is an additional window which asks if you want to install a plug-in. The first times I clicked "Later" then I clicked "Never", but I didn't install it. I don't know if that influences the NilObjectException behaviour.

.  
(Version 1.0)

ROB.H  Small, neat and does the trick. I did try to see if I could get it to crash following the steps the other reviewer mentioned, but didn't manage it - I ticked the two options then opened Preferences and the Preferences window appeared. Still, would be interested to hear what the developer says.

One observation regarding password protecting your Rar files is that you only type the password in once and the characters are hidden. Either you should have to type it in twice to confirm you haven't made a typo, or there should be a tick box to reveal the password you're going to use so you can check it. Without that you risk creating an archive you can't get back in to if you made a typo on setting the password.

Other nice features in future versions would be things like the option to automatically delete the original file(s) or folder(s) when the archiving finishes, etc.   
(Version 1.0)

BEAMY  Nice idea, but written with RealBasic, therefore say Hello to "NilObjectException" and the program "must shut down"...

How to reveal the bug ?

Start the program, click the little "Gear" symbol in the main window, then "Use password" and "Create parts ..." appear and then go to the "RarMachine" menu and choose "Preferences" --> NilObjectException !

I tried it several times... always the same.

I am not going to pay $8 for this.

Maybe the next version is made with Cocoa and I can say ByeBye to "NilObjectException".

:-)  
(Version 1.0)