Open source Dylan was open sourced by a company called Functional Objects. The Macintosh Programmer's Workbench was never open source to my knowledge.
Since both of these are semi-obscure and incorrect it's obvious that you've just cursory searched for stuff you don't have direct knowledge of just to bass Apple (which has open sourced several things as well as provided changes back to the community, and not just when the license forced its hand).
MPW used to be available from "ftp://ftp.apple.com/developer/Tool_Chest/Core_Mac_OS_Tools/MPW_etc./", but Apple took their FTP server down. There's still a mirror.[1] It's mostly ".hqx" files, so you need to find something that can decompress old Stuffit files.
Open source Dylan was open sourced by a company called Functional Objects. The Macintosh Programmer's Workbench was never open source to my knowledge.
Since both of these are semi-obscure and incorrect it's obvious that you've just cursory searched for stuff you don't have direct knowledge of just to bass Apple (which has open sourced several things as well as provided changes back to the community, and not just when the license forced its hand).