[plt-scheme] PLT versions

From: Matt Jadud (mcj4 at kent.ac.uk)
Date: Mon Jan 2 23:09:58 EST 2006

1. Installing multiple versions on OSX

I found at various times that the PLT installer refused to let me 
install multiple versions. A solution that seems to work is to reach into


and remove all of the receipts pertaining to PLT Scheme; I believe these 
will be the receipts for the MzScheme and MrEd frameworks, in 
particular. Given that the PLT installer actually takes care not to 
overwrite any previous versions, these artifacts of the OSX installation 
process are not (I don't believe) critical to the operation of 
Mz/DrScheme on your machine.

I currently have 209, several versions of 299.X, and 300 installed from 
the binary installers; the conflicts are generally minimal, although the 
Help Desk was occasionally wonky in the middle of those versions---for 
reasons I never really cared to understand or explore.

2. The transition from v209 to v300 was significant; there have been 
changes throughout the language. MrEdDesigner most likely suffers from 
differences in the class system and how strings are handled; that's an 
off-the-cuff guess based on having looked at the code many moons ago.

Hope that helps a bit.


Nicholas Chubrich wrote:
> I'm just starting out with PLT (after having used MIT before).  In trying 
> to work with a package (MrEdDesigner) I find that it works with v209 but 
> not v299.  Is this generally true of packages and modules (found on PLaneT 
> for instance) that they will not work with later versions of PLT?  Can 
> they be made to work?  If not, what is the best way of installing multiple 
> versions of PLT (on Mac OX) so that they do not conflict?
> Thanks,
> Nick Chubrich.
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