[plt-scheme] PLaneT package repository is now available

Users of recent versions of exp-tagged PLT Scheme will find that an 
alpha version of the PLaneT package repository is now functional. The 
PLaneT package repository is a system for automatically distributing and 
installing Scheme code that works by extending the normal module-require 
system with a new require form:

(require (planet "test-connection.ss" ("planet" "test-connection.plt" 1 0)))

downloads and installs the latest version of package 
"test-connection.plt" owned by user "planet" (failing unless that 
version is least 1.0), and once installed requires the file 
"test-connection.ss" from it. (Try that require-line out in DrScheme, by 
the way: if PLaneT is installed and working on your system a window will 
pop up telling you so.)

Because it's integrated with the require system, programs you write that 
require planet packages will automatically download and install those 
packages on users' machines if the users don't already have acceptable 
versions installed. This should make it much simpler to distribute 
programs that depend on libraries.

For a list of currently available packages, visit

http://planet.plt-scheme.org

To submit a new package, follow the directions in 
plt/collects/planet/doc.txt.

Remember, the PLaneT system is alpha-quality. There are bugs and 
features that really ought to be implemented but aren't yet. Please send 
me feedback, and don't make your Fortune 500 company dependent on it 
just yet. :)

-jacob