DEVELOPMENT SITE HAS MOVED! For more information please see the official site at: http://rsgallery2.net/
RSGallery2 is a nice joomla 3 extension. It is free for personal and commercial use and i like it. Of course as i am one of the actual developers you may not trust my review ;-) The given release here is really old. I will mail the authors. However if you are looking for a release or documentation the actual website is www.rsgallery2.nl or www.rsgallery2.org. Release can actual be found on joomlacode but that will change within the next month (05/2015) Have fun with free open source gallery RSGallery2 for Joomla!