Currently (the latest nightly build), the names of Planet 2 packages are restricted to use only the characters a-z, A-Z, _, and -. The current set of Racket collections, on the other hand, uses a-z, 0-9, and -. Planet 1 also has several packages using 0-9. We need to add digits to the set of valid names if we want 2htdp, algol60, planet2 (itself!), r5rs, and r6rs to be "package-friendly". I know if I were to release a package named after ACL2 somehow, I'd be hard-pressed to figure out what to do with the "2". Planet 1 packages and Racket collections also don't use A-Z (with one or two exceptions on Planet). In theory, we could disallow those characters and gain compatibility with case-insensitive mediums such as the default Mac OS X filesystem. I'm not particularly attached to this second proposal, but since it leads to potential errors I thought it was worth bringing up. If we leave both cases in, we at least need to make sure programs that run on Windows and Unix don't break on Mac due to package names conflicting on the filesystem. Carl Eastlund