You can go ahead and check out the current version of the BaseTen framework with Subversion:

 svn co http://basetenframework.org/svn/trunk baseten

BaseTen has several subprojects, namely BaseTenAppKit and a plug-in for Interface Builder 3. The default target in BaseTen.xcodeproj, BaseTen + GC, builds them as well; the plug-in and the AppKit framework will appear in the subprojects’ build folders, which are set to the default folder. The built files will probably be either in build folders in the subprojects’ folders or in the user-specified build folder. The documentation will be in the Documentation folder.