Marble is a virtual globe

Virtual globe

A virtual globe is a 3D software model or representation of the Earth or another world. A virtual globe provides the user with the ability to freely move around in the virtual environment by changing the viewing angle and position. Compared to a conventional globe, virtual globes have the...

 that allows the user to choose among the Earth, the Moon, Venus, Mars and other planets. It is free software

Free software

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

 under the terms of the GNU LGPL, developed by KDE

KDE

KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...

 and the free-software / open-source communities for use on personal computer

Personal computer

A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

s running a Qt4-compatible operating system.

Marble is intended to be very flexible; beyond its cross-platform design, the core components can easily be integrated into other programs. It is designed to run without the need for hardware acceleration, but it can be extended to use OpenGL

OpenGL

OpenGL is a standard specification defining a cross-language, cross-platform API for writing applications that produce 2D and 3D computer graphics. The interface consists of over 250 different function calls which can be used to draw complex three-dimensional scenes from simple primitives. OpenGL...

.