I have a Rails app running on Mac at http://localhost:3000 and I would like to access it from Windows 7, which is a guest OS running on VirtualBox.
Can you explain me how to do that?
Make sure networking is active in the virtual machine and you can web browse, etc. from the Windows machine. Then you can enter the ip address of your Mac and the port in the web browser of the virtual machine and it should come up for you.
You can get your Mac's IP address from the system preferences (networking) or using ifconfig on the terminal application. Then use http://xxx.yyy.aaa.bbb:3000 and your app should pop up for you.
Just in case others read this more recently... by doing ifconfig or ipconfig /all (in windows) guest.. you can get yor gateway ip.. which will be your host...
thus say your gateway is 10.x.x.x in guest... (and on host it is somethign else), just
try http://10.x.x.x/ (add port as desired).