Ruby on Rails

and couldn't display http://localhost/most/rannumgenerator/index     (rannumgenerator is controller I generated in most project).

Wonder if something that I should do for Mac Mavericks or some setting for Apache that I am not aware?

You may need to look in your error log (probably in /var/log/apache2/) for more details on what happened to Passenger.  Also, I've never tried accessing Rails projects under a subdirectory like that, you may need to see if you need to set up something specifically to handle that.

I set my system up quite a bit differently to easier support working on different projects.  First, since Mac OS updates can overwrite http.conf, I put my custom config in the /etc/apache2/other/ directory, broken up into separate files.  So, I have a passenger.conf file and a vhosts.conf file.  I create entries in /etc/hosts to set up local domain names for my various projects.  So I end up with something like this:

/etc/hosts:

127.0.0.1       my.greatproject.local

/etc/apache2/other/passenger.conf:

LoadModule passenger_module /Users/jcrate/.rvm/gems/ruby-2.1.2@global/gems/passenger-4.0.45/buildout/apache2/mod_passenger.so

<IfModule mod_passenger.c>

  PassengerRoot /Users/jcrate/.rvm/gems/ruby-2.1.2@global/gems/passenger-4.0.45

  PassengerDefaultRuby /Users/jcrate/.rvm/gems/ruby-2.1.2@global/wrappers/ruby

</IfModule>

/etc/apache2/other/vhosts.conf:

<VirtualHost *:80>

    ServerName my.greatproject.local

    DocumentRoot /path/to/project/public

    RackEnv development

    PassengerRuby /Users/jcrate/.rvm/gems/ruby-2.1.2@myproject/wrappers/ruby

</VirtualHost>

If you're not using RVM, then your passenger-related paths will look a little different.  However, if you have more than one Rails project, you probably want to be using RVM or some sort of ruby version manager.