10. full text search. (class decorator for model?)

26. orm for nosql? such as this one: http://qslack.com/projects/rhino-a-ruby-hbase-orm/

27. ref_grandchildren can't access some attributes of grandchildren. for example: everblog project: tag.blog_entrys.lang report an error.

30. generate visual charts according to model. It is good for analyzing and demonstrating.

36. multiple many_to_many between two models

37.