There are a number of efforts out there that share some of the purpose of Dynamo Nodes. For instance, the Dynamo Primer lists details of certain core nodes, as does Enjoy Revit for list actions.

Obviously, Dynamo Nodes aims to be a unified portal for Nodes, which includes Custom and Core Nodes, along with the opportunity to Search, Tag, Rate, and Comment on specific nodes and their use.

A similar indexing or glossary effort was undertaken by Thomas Vogt, and his work has been collected in a Node Book for Dynamo. You can download the Node Book for Dynamo v2 at:
https://www.dropbox.com/s/ws30t8uhtlx8jqq/Node-Book_for_Dynamo_v2.xlsx?dl=0

I would sincerely encourage anyone who wants to work on a glossary or index like this to contact me and I will invite you as a Contributor here on Dynamo Nodes. If we work together we will be able to make and maintain the best resource for Dynamo Nodes on the web.

Quote from Thomas Vogt:
This is a new version of the node book, but I have no time to completely finish it. Maybe some of you can use it anyway for something… https://www.dropbox.com/s/vlbo5axawtllgpk/Node-Book_for_Dynamo_v2.xlsx?dl=0

Source:
https://www.linkedin.com/groups/6510470/6510470-6114521488193261570