Looking for something on Mac Os and Linux mostly, and GUI, not just the command line tool. Anybody has experience using Syncro SVN Client http://www.syncrosvnclient.com/ ?
Why use a multi-platform tool? The good thing about svn is that you can use one tool on Mac OS, and a completely unrelated tool on Linux, but they'll all still talk to the same repo. On Mac, I'd recommend Versions.
Netbeans is cross platform and has a plugin that enables subversion. An excellent IDE if you ask me...
In a Venn-diagram sense, you are cutting it close by a Boolean AND between a) sane cross-platform GUI clients and b) SVN clients. I'd forgo some of the requirements -- I personally like the cmdline versions as well as as the Emacs interfaces on all platforms I use, and I occasionally use the kdesvn GUI on Linux.
Edit: Oh wait, there is one: Qt Creator is a wonderful IDE, is cross-platform and has SVN integration.
for multi-platform (and even if you need a good client for one platform) I'd recommend SmartSVN: http://www.syntevo.com/smartsvn/index.html
They have a free Foundation Edition available. Since it's a java tool, it works on almost all OS.
Would RapidSvn located here - cross platform written in wxWindows/C++ do?
Hope this helps, Best regards, Tom.