In 2021, Derek Murphy and Mitchell Zemil released a documentary series about old video game worlds and communities.
One episode is about ZZT and you can watch it
here or
here. More details
here.
In 2014, Anna Anthropy released a book about ZZT, its users, and the communities that formed around it.
She interviewed several people to help tell the story, including me. You can find it
here.
ZZT Comics
These are by Nomad.
Hercules Meets Tim Sweeney
An interview with the creator of ZZT.
ZZTers Anonymous
Something that I inherited.
Megazeux
ZZT's more advanced cousin.
Miscellaneous:
Kudzu as zzt.org CGoTM