GeoGebra is a free mathematical program with many opportunities in the field of geometry, algebra, and various calculations. Allows you to build charts, drawings, curves, to perform operations with matrices, complex numbers, work with tables and much more.
*From elementary school to university level
*Interactive geometry, algebra, statistics, and calculus software
*Tens of thousands of free materials
To work with the program is very convenient. Charts are constructed using simple mouse pointer movement or placement of the required points. All control points are added to the list in the left part of the window. Any point you can edit the keyboard and dragging it with the mouse.
Each object can be configured as desired. Change color, label, width, to set the display conditions, to specify actions when clicking on the object.
The program is written in Java and is cross-platform. Available for Linux, Windows, Mac OS X, iOS, Android. There are also Portable version that runs without installation. I should also mention the Web version of the software (GeoGebra Web Application)that runs directly in the browser: http://web.geogebra.org/chromeapp/
Installation into Linux Mint: