Can I run Merb on Mac OSX Tiger?

Merb Stack uses SQLite3 by default, make sure you have it installed.

G5:~/Sites/my-first-app John$ rake db:automigrate
(in /Users/john/Sites/my-first-app)
Loading init file from /Users/john/Sites/my-first-app/config/init.rb
Loading /Users/john/Sites/my-first-app/config/environments/development.rb
Loading init file from /Users/john/Sites/my-first-app/config/init.rb
Loading /Users/john/Sites/my-first-app/config/environments/development.rb
 ~ Connecting to database...
dyld: NSLinkModule() error
dyld: Symbol not found: _sqlite3_prepare_v2
  Referenced from: /usr/local/lib/ruby/gems/1.8/gems/do_sqlite3-0.9.6/lib/do_sqlite3_ext.bundle
  Expected in: flat namespace

If you have MacPorts setup:

sudo port install sqlite3

And reinstall do_sqlite3 (Data Objects SQLite3 driver):

sudo gem install do_sqlite3