Map: New Large Map Latus

[Ballbarian]

Alderanas,
If you are a windows user, you can download a trial version of WinRAR from here:
http://www.rarlab.com/

(It used to be shareware with a nag screen after the trial was over. Not sure if that is still the case in newer versions or not.)

[Agrajag]

You could also try 7z, it can open all common compression files, has awesome compression if you use its own format, and if someone decided to post a .7z file because they are smallest, you'll still be able to open those