Although the puzzle sections of the Internet's largest software repositories boast many dozens or hundreds of titles, once you get past all the clones of stock games like Mastermind and peg solitaire, not very much remains. Well-presented original puzzles, especially freeware ones, are few and far between.

Runes is a puzzle game with a distant family resemblance to Sokoban, in that your task is to move pieces around the small (8x8) board by "pushing". As in Sokoban, the pieces can only be pushed if the square in front of them is empty. The edge of the board, other pieces, and "wall" squares provide the obstacles that limit movement.

Pushing the pieces in Runes is accomplished by clicking arrow squares at the margins of the board (the orange and green triangles in the illustration). The objective of the game is to clear the board of pieces, of which there are four kinds, each marked with its own rune:

Pieces are removed from the board when brought into edgewise contact with another piece or pieces of the same type. The two pieces on the left above are removed when two or more come into contact. The two on the right are removed only if three or more meet.

Runes is not mind-numbingly difficult, but provides a pleasant challenge that you can pick up for a few minutes of relaxation when the mood strikes you, and put down again after solving a level or two. It should run comfortably on any Windows 95 or better system with a High Color (16-bit color) or better display.

If one must play games (and it appears that one must), solitaire card games have a lot to recommend them. They're quick, fun and cheap. Depending on the game you choose, you can get as much or as little challenge to your powers of reasoning as you may want on a particular occasion. But solitaire can also be a little tedious. In the first place, there's the bother of shuffling and dealing, particularly onerous in games with big layouts requiring two decks. There's the problem of finding a pack of cards and sufficient table space. Finally, unless one has an encyclopedic knowledge of the games, one has to make do with the same few stale variations over and over again.

Dave Bernazzani's Solitude freeware retains most of the advantages of physical solitaire, while eliminating all the inconveniences. No more shuffling and dealing - the program does both instantly. No more chasing down cards and clearing tables. And no need to make do with only a handful of games: Solitude knows 91 of them, from Aces Up, Alhambra and Amazons to Will o'the Wisp, Windmill and Yukon - knows how to deal them out, how to conduct the play, and how to explain the rules to you. Each game is rated for approximate playing time and victory odds.

Solitude's look is plain but serviceable. Four of the games require a 1024x768 screen. The rest are about evenly split between those that need an 800x600 screen and those that can get by with 640x480. Display size aside, any computer capable of running Windows 95 will have no trouble with this game.

The well-known geometrical Tangram puzzle, said to be of Chinese origin, has long attracted mathematicians, as well as puzzle fans, because of the many ways of arranging the seven simple pieces in the set. Toystore versions of the puzzle usually come with the seven pieces packed into a square tray. Reassembling the square after shuffling the pieces is the first puzzle most people attempt, but an infinitude of pleasing arrangements is possible.

Mark Overmars, a Dutch computer scientist, has created a computer version of the Tangram that, like the original puzzle, is both simple and full of possibilities. He provides a host of built-in puzzles of varying complexity. The simplest ones are suitable for small children; the most complex will challenge adult puzzlers. An editor is provided as a separate program, for those who would like to create their own tangram puzzles. Clear on-line help is also provided.

Tangram will appeal to anyone who enjoys our own freeware geometrical puzzle, Oktagon, and vice versa. The game needs Windows 95 or better, and should run on just about any hardware. It is suitable for players of any age who enjoy the challenge of a geometrical puzzle and, since most puzzles require only a few minutes to solve, is well suited to those whose busy schedules demand that they take their recreation in small doses.

The Sokoban puzzle game, ingenious and well-known, originated in Japan, where "sokoban" means "warehouse-man". It belongs to that rather small class of puzzles whose elegance could have been appreciated in any age, but whose implementation had to wait for the computer.

For those who may not have encountered it before, Sokoban is a quiet game that demands ingenuity and persistence rather than reflexes and dexterity. This version provides dozens of levels - each a separate puzzle - plus an editor with which you can design your own. If you come up with a good level, share it, as others have done, through the author's web-site.

SokoMind is suitable for puzzle-lovers of all ages from perhaps age nine or ten and up. It should run satisfactorily on just about any Windows 95 or later computer.

The combination in one person of an expert programmer and a keen hobbyist can produce remarkable software. That is the case with this superb astronomy program by the brilliant John Walker, whose Fourmilab web-site is worth a leisurely tour even if you come away without downloading any of the fine (and free) programs he has written.

Home Planet has far too many features to list, but a core attraction for most users is the ability to display a detailed view of the night sky - your night sky, at any time of day and any place on Earth - complete with star names and constellation diagrams. Would you like to see on a map which parts of the world are sunlit, right now, and which are in darkness? Would you like to have a bird's-eye view of the solar system, and find out where Earth is now in relation to our planetary neighbors? Home Planet will show you these things and much more.

The program is full of learning opportunities, well supported by comprehensive and lucid on-line help. A budding interest in astronomy, whether of an adult or a child, will find much nourishment here.

Home Planet requires a decently fast computer (Pentium 100 or better), and a reasonable tolerance for numbers and scientific jargon on the part of the user (younger children will need adult assistance). The full program makes for a long download (most of an hour with 28.8 Kbps connection), but a "lite" version is available on the web-site if that is a concern. The link here is to a 32-bit (Windows 95/98) version, but an older version for Windows 3.1 is also available.