Finding out some free and good SVN tools for Ubuntu / Linux, I found the following ones:
RabbitVCS / NautilusSVN
RabbitVCS / NautilusSVN is one of the best SVN tool, and an alternative to Tortoise SVN for Ubuntu / Linux, Debian, Fedora. RabbitVCS is inspired by TortoiseSVN and others.
To find out more about RabbitVCS / NautilusSVN, check out the following post:
RabbitVCS / NautilusSVN, Tortoise SVN Alternate Ubuntu
RapidSVN is also a good SVN tool for Linux / Ubuntu after RabbitVCS / NautilusSVN. It is a cross-platform GUI front-end for the Subversion.
To find out more about RapidSVN, check out the following post:
RapidSVN, Free SVN Tool Ubuntu / Linux