[plt-dev] Release Announcement for v4.2.4

On Mon, Jan 25, 2010 at 10:32 PM, Eli Barzilay <eli at barzilay.org> wrote:
> * Added a porting guide that explains how to turn `htdp/world'
>  programs into `2htdp/universe' and `2htdp/image' programs.

Replace the above with this:

* In support of 2htdp/image, the 2htdp/universe library no longer explicitly
  provides an image library. See the (new) porting guide for more details.

> * [Matthias] `error' in teaching languages?  universe/world changes?
>  `random', `gensym', `current-millisecond', `sleep', `assoc',
>  `with-i/o-from-to' added?

I think error at least deserves a mention here:

* error in the teaching languages now accepts any arguments and puts
them together into an error message.

The other stuff sounds too small, but deserves to be in some more
comprehensive list of changes to the teaching languages.

Robby