(All for Mac OS X:)<p>There's a beautiful app, Versions, <a href="http://www.versionsapp.com/" rel="nofollow">http://www.versionsapp.com/</a>, but it's around US$50. That's the one we use.<p>There's SvnX, <a href="http://www.lachoseinteractive.net/en/community/subversion" rel="nofollow">http://www.lachoseinteractive.net/en/community/subversion</a>, which is free but ultimately not very good (in our experience).<p>There's ZigVersion, <a href="http://zigversion.com/" rel="nofollow">http://zigversion.com/</a>; no opinion.<p>But, really, a 5-second effort with Google would turn up all of this and more:<p><a href="http://en.wikipedia.org/wiki/Comparison_of_Subversion_clients" rel="nofollow">http://en.wikipedia.org/wiki/Comparison_of_Subversion_client...</a> .
You can just download the binaries for the client (<a href="http://subversion.tigris.org/" rel="nofollow">http://subversion.tigris.org/</a>). If you want menu and icon support when browsing files, there's SCPlugin for the Mac's Finder or TortoiseSVN for Windows. If you want a GUI, note that the Mac's native Xcode environment has Subversion support built-in.