WorldWide Telescope (WWT) enables your computer to function as a virtual telescope, bringing together imagery from the best ground and space-based telescopes in the world. Experience narrated guided tours from astronomers and educators featuring interesting places in the sky.

Choose from a growing number of guided tours of the sky by astronomers and educators from some of the most famous observatories and planetariums in the country.

A web-based version of WorldWide Telescope is also now available.

From author's site:

Super Tux Kart is a 3D kart racing game based on TuxKart with funny characters, featuring Tux and friends. It is a fun-racer game, focusing on fun and ease of play.

Swarm is a newest remake of classic Space Invaders game. Your thrilling mission is to collect priceless crystals and put down the relentless alien race that is in your way and intent on stopping you.

Featuring excellent graphics and sound, Swarm brings addictive action to your PC for endless hours at a time.

From author's site:

josé is a graphical Chess tool. You can store chess games in a database (backed by MySQL). You can view games and edit variations and comments. You can play against a "plugged-in" chess engine and use it for analysis.

josé is packaged with the Toga and Spike chess engines.
However, there is a huge number of freely available -and commercial- engines that you can also use with jose:

Features:

* graphical frontend to MySQL database
* read and write PGN (Portable Game Notations) files
* 2D and 3D view
* edit games, insert comments, variations
* plug-in chess engine for play and analysis; supports both XBoard and UCI protocol.
* Play Fischer Random Chess / Chess 960, or Shuffle Chess
* Opening Books
* ECO opening classification
* Position Search

From author's site:

Brutal Chess features full 3D graphics, an advanced particle engine, and several different levels of intelligent AI, inspired by the once popular "Battle Chess" released by Interplay circa 1988.

Capable freeware, lightweight (small size)computer chess program. Plays a fairly strong game. Chenard automatically learns new openings. You may choose how many seconds the computer should think. Readable log of the game. Chenard can speak the notation for each move played in the game.

Microsoft CART Precision Racing trial version, now features an additional new oval track, Miami, and several performance improvements!

From author's site:

Star Defender is a superb remake of the famous game also known as Galaga, Galaxians or Space Invaders. You are a test pilot flying the Tornado spaceship. Your ship is controlled by your mouse. The ship is limited to movement in the lower line of the play area. Tornado can have up to 5 levels of power-ups.

Each level gives you both more life and a more powerful weapon. Every time you are hit, you will lose 1 power level. When all power levels are depleted, your game is over. To fire, press the left mouse button. If you have rockets - press the right mouse button.

Shoot-em up Space war! The chickens have returned with an organized invasion to take over the entire solar system! Journey to each planet and fight your way through to save the world!

From author's site:

Space Invaders Clone. Based on old arcade-classic Space Invaders. Game features nice vintage graphics and sounds, not to mention cool soundtrack. Gameplay is extremely simple yet challenging and addictive.

The classic Asteroids with modern graphics.

EclipseCrossword is the fast, easy, free way to create crossword puzzles in minutes. It's never been simpler—just give EclipseCrossword a list of words and clues, and it does the rest. In seconds, you'll have a crossword puzzle with just the words you want.