The Ruby Toolbox - Know your options!

awesome_nested_set

2.05
An awesome nested set implementation for Active Record
 Popularity
Downloads
3,548,480
Stars
2,021
Forks
424
Watchers
52

ancestry

1.96
Ancestry allows the records of a ActiveRecord model to be organized in a tree structure, using a single, intuitively formatted database column. It exposes all the standard tree structure relations (ancestors, parent, root, children, siblings, descendants) and all of them can be fetched in a single sql query. Additional features are named_scopes, integrity checking, integrity restoration, arrangement of (sub)tree into hashes and different strategies for dealing with orphaned records.
 Popularity
Downloads
2,886,555
Stars
2,546
Forks
357
Watchers
59

closure_tree

0.74
Easily and efficiently make your ActiveRecord model support hierarchies
 Popularity
Downloads
634,066
Stars
1,156
Forks
165
Watchers
40

acts_as_tree

0.68
A gem that adds simple support for organizing ActiveRecord models into parent–children relationships.
 Popularity
Downloads
1,848,559
Stars
455
Forks
77
Watchers
24

chris/better_nested_set

0.09
better_nested_set Rails plugin (my fork from official SVN)
 Popularity
Stars
62
Forks
17
Watchers
2

rails/acts_as_nested_set

0.07
NOTICE: official repository moved to https://github.com/bbommarito/acts_as_nested_set
 Popularity
Stars
69
Forks
11
Watchers
6

acts_as_ordered_tree

0.04
ActiveRecord extension for sorted adjacency lists support
 Popularity
Downloads
72,942
Stars
26
Forks
10
Watchers
3

arboreal

0.02
Arboreal is yet another extension to ActiveRecord to support tree-shaped data structures. Internally, Arboreal maintains a computed "ancestry_string" column, which caches the path from the root of a tree to each node, allowing efficient retrieval of both ancestors and descendants. Arboreal surfaces relationships within the tree like "children", "ancestors", "descendants", and "siblings" as scopes, so that additional filtering/pagination can be performed.
 Popularity
Downloads
38,054
Stars
10
Forks
4
Watchers
1

acts_as_dag

0.02
Adds directed acyclic graph functionality to ActiveRecord.
 Popularity
Downloads
62,510
Stars
15
Forks
3
Watchers
4