Extensions provide helper or class methods for Sinatra and Padrino applications. See the Sinatra extensions page for more information about this topic.
We also have some 3rd party extensions (ex: for ActiveRecord/MongoMapper/DataMapper, etc..) that are useful for web developers.
If the extension is a gem put it in Gemfile otherwise create a file under your lib directory.
|What|Description|Where| |:---|:----------|:----| |Exception Notifier|Sends an email when an exception is raised|gist| |Auto Locale|Sets for you I18n.locale parsing path_info|gist| |Locale|Translates ActiveRecord attributes|gist| |Permalink|Generates ActiveRecord permalinks for your fields|gist| |Flash|Helps setup cookie sessions with swfupload|gist|