These are mods or mod experiments that have been abandoned by their original creator, their maintainers or website hosts. In some cases failed attempts have been made to update the mods but, well, they failed. Anyway, those mods contain ideas or concepts too interesting to be left in the vaults. This is expert stuff and quality is what it was when the creator left the work aside - this is often at very high standard nonetheless.
The current restored versions should be playable in EE and EET games for those who dare to venture. There is no playable "official" version to be found and it is too complex and cumbersome to issue fixpacks to make them work in EE and EET, that is why I opened my local files to those who would like to try them because maybe you have been looking for them a long time already in the new games?
Note - All these ressurections may work on classic games as well but this is not tested, technically they contain nothing obvious that could prevent it.
I can only provide support/enhancement for those versions above and for the EE/EET context.