Granted I haven't researched much but from what I see it seems ROR is installed under one directory. For example, with CakePHP you can have your entire structure under one directory or move the core to another directory for multiple sites to access. Can you do this with ROR as well?
Also, before I start seriously considering learning this, do I have to use the command console to build my scripts or even setup ROR? It seems from what I've read that is the case.