The XO has got too much Sugar

The XO’s default user interface, Sugar, is very interesting. Its goal is to allow for kids to collaborate, and in doing so, enhance their learning. It is a wonderful idea. The only problem is that it leaves them with a computer that has got barely any memory and no swap (XOs haven’t got swap).
I did a little testing tonight, booting the computer cold, connecting to wifi, and then checking the memory with the ‘free’ command. Here is what I found:

Total MB Used MB Free MB
Sugar 232 220 12
FVWM 232 113 118

I suspect that the result of this is that kids have to be extremely diligent about how many programs they are running. In my experience it is pretty easy to bog the thing down to a stop; just hand it to someone used to operating any other computer; they start three programs, and the operating system will out of memory.
This decision must have been made for a good reason, though. It would be interesting to find it out. I won’t pursue that right now. Anyone happen to know?

Wifi-radar hoses my wifi router

If you don’t run Sugar on your XO, you need to configure your wireless connection somehow, and a lot of folks use wifi-radar, myself included.
While experimenting with it tonight, I noticed that the wireless connection on my other computer quit working periodically. Eventually I did put two and two together and found that everything worked fine when I wasn’t running wifi-radar!
Resolving this is of low-priority.

Peter Ivanyi's Dialog Library

Peter’s library provides a way to design user interfaces in XML.

The user specifies the layout of the dialog window in XML. The interaction is also specified in a simple way, setting values or labels and setting actions which should occur when the user clicks on the specific widget. An example can be found in the package.

(via PLT Discuss)

Larceny Scheme

Larceny is a simple and efficient implementation of the Scheme programming language. Created originally as a test vehicle for research on garbage collection and compiler optimizations, Larceny has grown into a major multiplatform system, and is currently the only implementation that supports all four de facto standards for Scheme: IEEE/ANSI, R5RS, ERR5RS, and the R6RS.

Setting the memory limit in DrScheme

When you use DrScheme, you should be sure to set the memory limit by going to the menu-item:

Scheme->Limit Memory

Doing so allows DrScheme to “play nice” with the operating system when you write some code that eats up all of the free memory. Rather than taking the whole operating system down; DrScheme dies gracefully.