Exploring the contents of Standard Library 6.12 turns up a number of design details that are not well-documented. It is clear that significant changes have been made since the 6/11 version.
Who originally wrote all of these changes? What was the timeline for development? Is there any documentation beyond the items already captured in the sticky post of I6 resources that are relevant to understanding the library’s current contents, or is it simply a matter of reading and deciphering the existing code?
Most of the changes between 6/11 and 6/12 were taken from https://gitlab.com/DavidGriffith/inform-2006. That was an abortive attempt to produce Inform 6.40 that fizzled out in 2006. I obtained the CVS repository from @DavidK (I think) in 2015 and converted it to Git to support my effort to get the Standard Library up to date.