Free planet rock software for linux

Planets is a simple interactive program for playing with simulations of planetary systems, released under the GPL. The project runs on Linux and Windows, and could doubtless be ported to your favorite flavor of Unix.
Planets was originally designed for kids, in particular, for my then 4-year old nephew who is fascinated by astronomy. The user interface is aimed at being simple enough that a fairly young kid can get some joy out of it. But the adults who have used it have found it to be pretty fun as well.
The code is not bug-free, and Planets is missing some significant features. But its pretty stable and is a fun toy to play with. If you do download it, please drop me an email and tell me about your experience with it.
Main features:
- Saving and loading of universes
- Infinite undo (erase last action) and goback (return to point in time just after last action). This allows for undoing mistakes and replaying interesting configurations.
- Traces of planet trajectories
- Two ways of dealing with planet collisions:
- merges, where the colliding planets are merged into one planet, and
- bounces, where the colliding planets are bounced off each other elastically. This itself comes in two varieties:
- force bouncing, where the force between planets is made repulsive at close quarters.
- true bouncing, where simple pool-table physics calculations are made to determine when planets collide, and compute the appropriate bounce from said collision.
- kidmode, a mode where the focus is (mostly) locked on the application, and interesting changes are initiated by merely banging on the keyboard. This mode is aimed at 1-5 year olds.
- Center-of-mass following: it is possible to follow the center of mass of a subset of the planets. Thus, if you have a sun-moon-planet system, you can have the view automatically track the moon-planet pair.
- Can display kinetic, potential and total energy of the system.
- Both the gravitational constant and the gravitational exponent can be changed.
- There is a simple control panel that makes it possible to see and change the simulation options.
- Zooming, panning, and centering on the center of mass.

xplanets shows a simulation of a spacecraft flying through the solar system. With the controls next to the simulation screen you can control the simulation and steer the spacecrafts flight.
The following planets are visible:
- the Sun (yellow)
- mercury (gray38)
- venus (burlywood2)
- earth (blue2)
- mars (LightSalmon3)
Note that the sizes of the sun and planets are not to scale, though their distances are. Showing the planets to scale would mean that they wouldnt be visible. The solar system is rather big, after all.
The planet nearest to the spaceship is indicated with a red circle around it. Its relative speed and distance are shown in the data display.
The xplanets program uses the GTK+ toolkit. It has been built with version 2.2.1, so it should work with any version >2.0.0. It does not work with GTK+ 1.x anymore.

Thinking Rock project is a Java based software application for collecting and processing your thoughts, following the GTD methodology.
Thinking Rock allows you to collect your thoughts and process them into actions, projects, information or future possibilities. Actions can be done by you, delegated to someone else or scheduled for a particular date. Projects can be organised with ordered actions and sub-projects. You can review all of your actions, projects and other information quickly and easily to see what you need to do or to choose what you want to do at a particular time.
Main features:
- It will help you to store in one safe place all the things you have to do or would like to do one day;
- Unlike many task management applications, Thinking Rock lets you to group your actions in projects and sub-projects;
- It gets you moving on your thoughts by encouraging you to think of the next physical action to take;
- It is simple, easy (help documentation provided) and quick to use ;
- We provide free customer support;
- The data file is separate so you can have the application installed on your home computer and at work, and transfer the small data file between computers;
- It is multi-platform: use it on Linux, Machintosh, or Windows;
- Its free.

Wait no more for a usable system to create a centralized hub, so-called a planet site, of news feeds from selected Web sites, PlanetMatter provides a better choice to aggregate RSS and ATOM feeds of blogs, company news, databases, calendars, articles, and more!

Lastest news items are instantly aggregated and sequentially laid out in one page for readability. Moreover, "full-text" search facility effectively retrieves more related news items according to search terms (keywords).

Features:
PlanetMatter comes with complete feed management features such as

Add, pause, delete, edit feeds
Import feeds to OPML or text
Edit planet site configuration information
and much more!

Installation:
PlanetMatter is relatively easy to install. Please read the INSTALL file for details.

Puntal is a light content managment system based on PunBB. Puntal does not modify any files of PunBB, but adds six standard modules (news, download, calendar, related pages, planet, and lexicon). 15 options can be enabled or disabled to fit your needs.
A plugin system can be used to add modules easily. A control panel like the one for PunBB is available. Puntal uses the style sheets of PunBB for perfect integration between the portal and the forums. Multiple languages are supported.
Enhancements:
- [bug] fix the install process(foxmask)
- [security] add check date in calendar (foxmask)
- [bug] fix the error call in lexique admin(Morph1er)
- [enhancement] add better url-rewriting(Morph1er)
- [enhancement] fix duplicate content index.php(Morph1er)

Panda3D is a free 3D Engine.
Panda3D is designed to reduce the time and cost of game development. It features an unusually short learning curve, an extremely straightforward API, and strong resilience to user error.
It is ideal for projects where the amount of time is limited, especially for game development houses that have to produce games quickly, or for instructors who want their students to be able to finish a game in a few weeks.
Main features:
- Short learning curve
- Rapid development
- Library callable from C++ or Python
- Rock solid stability
- Free software license
- Support for Windows and Linux
- Simple installation
- Collection of free models and artwork
- Multiple active development teams
- Disney Imagineering
- Entertainment Technology Center
- Lots of documentation
- Extensive manual
- Collection of code samples
- API Reference materials
Enhancements:
- Fixed sound system that would not initialize properly under Linux.
- Panda DLL names now all start with "libp3" or "libpanda".
- Fixed normals reversed in heightfield tesselator.

GNU Robbo project is a game ported from the Atari XE/XL.

The player has to rescue Robbo the robot from an unfriendly planet and help him collect all the parts of a capsule so he can go to another level.