Tweet data extraction operations involve the use of suitable API libraries, which provide all the tools and services to retrieve user tweets and their correlated information. When a user posts a tweet on Twitter, besides the text content of 140 characters, he/she can share other useful information such as videos, images or GPS coordinates. Considering a given emergency event, this information could be useful to accurately locate the area where the event is occurring and to better coordinate rescue operations. In the state-of-the-art there are several APIs (Application Programming Interfaces) which provide useful tools to collect and analyze tweets shared by users. In general, it is possible to distinguish official Twitter libraries and unofficial libraries created for specific programming languages (i.e. Neo4J source: http://neo4j.com/). Usually the unofficial libraries use the core libraries of the Twitter APIs to retrieve data from the Twitter server but are customized for specific purposes. Twitter APIs are the official programming libraries proposed by Twitter (source: https://dev. Twitter.com/). These APIs allow different type of operations to be performed such as the extraction of tweets from Twitter streams or creation of custom applications for websites. They are freely available although they can be used with some limitations (see “Twitter APIs limitations” section). Twitter APIs can be generally classified into four groups: 1) Twitter for Websites, 2) Search APIs, 3) REST APIs, and 4) Streaming APIs.