Leonardo is a open source drawing tool for the 21st century. Leonardo is an open source vector drawing program named after the 15th century painter, but aimed for the 21st century user. By this, we mean it focuses on the place where the desktop and the web meet.
Leonardo is a drawing & presentation program, but it's designed to pull in interesting webservices and data from the web, as well as be extended with plugins written in several scripting languages.

Leonardo need Java Runtime Environment.

The license of this software is Free, you can free download and free use this graphing software.