Original sentence: There are currently three imageboard software packages in widespread use: Futallaby, Kusaba, Wakaba
Edited sentence: Danbooru is a Ruby on Rails-based imageboard software that is released under a FreeBSD license.The Danbooru package is no longer in development, but remains publicly available.There are currently three Futaba-based imageboard software packages in widespread use: Futallaby, Kusaba, Wakaba.There are two primary types of imageboard software packages in widespread use: linearly-directed imageboards modeled closely after Futaba Channel (in which content is posted through hierarchical subsections of topical interest, usually denoted by a forward slash such as "/f" for female), and nonlinear imageboards modeled after Danbooru (usually indicated by the usage of controlled folksonomic vocabulary for topical tagging and search).Unlike other Futaba-inspired imageboard software packages, Danbooru and derivatives aim for a non-hierarchical folksonomic structure in which users are able to post content and content tags.shimmie2 is a derivative of Danbooru that is designed for ease of installation, operation and extension