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Scratch may be the ultimate object-oriented programming language. Developed by folks at the MIT Media Lab, Scratch is a programming language where you literally snap objects–blocks–together to build applications. Rather than procedures or functions, you drag graphic "blocks" around on screen and the order in which you hook them together determines how the resulting activity behaves.

Scratch includes blocks to move, turn, and bounce on-screen "sprites". You can speak and make sounds, draw, resize, and more. Control blocks allow you to loop and branch, test variables, and even follow your mouse.

With Scratch you can do interesting things without having to be a hard-core programmer. Designed for kids as young as 8 years, there is a large community for sharing activities. Scratch is designed to help users become familiar with the design process, while learning mathematical and computational ideas.

Scratch is available in both Windows and Mac versions, with work underway to release a Linux version by the end of 2007.

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If you have a question about a Mac, you’re going to find the answer in MacTracker. Processor speed, original operating system version, expansion slots–it’s all here.

MacTracker is the ultimate resource for all things Macintosh. Starting with the Lisa (Macintosh XL), you can see every computer and Apple-branded Mac-compatible device, such as printers, displays, scanners, operating systems, and extras (remember the iPod, kids?) that came out of Cupertino: pictures, specs, and even room for your own notes, with links to relevant Web sites and documents. There’s even a section for Mac clones. You can create your own “Smart Categories” to search and group information based on your own criteria, including your notes.

Along with the nitty-gritty specs, there are some cool images included with MacTracker. The info page for each system has a picture of the system, and for the computers, you can play the “Startup Chime”, and for some of the older systems, there is also a recording of the “Death Chime”–not a happy sound, that. Interesting historical tidbits are included also.

MacTracker is available in versions for MacOS 8.5+, OS X, Win2k+, and even iPod.

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Did you sleep through all the astronomy lectures in college? Do you still have problems finding the Big Dipper? Stellarium may be the answer.

Stellarium is an open source planetarium application available for Linux, Mac, and Windows. Set your observing position and see the sky as it appears. Did you ever wonder what it all would look like from the moon? You can choose any moon or planet from which to observe, as well as any terrestrial location. How about a different time? Set the time and date, and you can travel back, or ahead, in time.

Now about that Big Dipper: turn on labels to show you what you’re seeing. Fire up the constellation overlays and see if that really looks like a goat up there (Capricornus), or just a bunch of stars. You can dig deeper and look at deep sky objects among the constellations.

Stellarium features over 120,000 stars, as well as all the planets and their moons. There is a scripting feature that allows you to record and play back your own shows, and you can even use Stellarium to drive a telescope.

It’s too late to improve your grade, but you still have time to find Orion’s belt.

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In Pictures, a company that publishers computer books that rely primarily on pictures rather than words to show how to perform tasks, has released its entire catalog of books as free PDF files for a limited time. The titles includes books about Microsoft Office, web graphics applications, web programming, OpenOffice.org, and more.

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Ever wish that you could take a ride on a space shuttle? Celestia is a 3D simulation that puts you in the passenger seat for a ride around the galaxy. Celestia features all of the major astronomical bodies, along with many star clusters. If you can't find a particular celestial body, you can probably find it in the extensive add-on library. If you prefer sci-fi, you can download the Death Star from the Star Wars series and a laundry list of other fictional add-ons. The application is available for Windows, Mac, and Linux and takes up 12MB of hard drive space. The universe is yours to explore with Celestia.

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