During the past holidays I discovered several practical demonstrations of how good software should always be. It's difficult to comment some things that looks almost perfect and whose every detail is truly amazing. If they had been related with NMR, not only I would have cited them long before, but I would have closed the blog for good. (Is it more off-topic to write about NMR during the week-end or to write about other things on an NMR blog?).
Good software share this property with good games: you learn the manual in a matter of minutes and never have to read it again.
ChessPuzzle by Robert Silverman entertains you with 6237 selected chess puzzles and can also hint the next move when you can't find it by yourself. The board is small, so people with visual deficiencies should half the monitor resolution. The controls are intuitive and all of them have a keyboard shortcut, which I prefer. You can also play a normal game on the 2D diagram, which is more enjoyable than any 3D representation I have tried so far. ChessPuzzle is free.
WouldjaDraw is a simple yet powerful drawing program. It does not edit pictures: you start with an empty canvas and the basic drawing tools. Costs 29.95 USD.
Both programs require Mac OS 10.4.
The suite of Ear Training applications by Usama Minegishi and Hidemoto Katsura is almost as great. Still requires Mac OS X (don't know which version). They are the best programs in their field that I have ever seen. The whole bundle costs 19 USD, but each single product is also available at 9 USD.
For not giving the impression that this is is a single-platform blog, I am closing the post citing a little lovely puzzle-solving game named Mummy Maze, which runs on Windows too. The trial is free, the fun is granted.