Chinese reader here. When I was in college about 11 or 12 years ago, a previous version of it is considered as one of our textbooks for the Operating System course. Most assignment and homework is about to add or modify some modules into kernel 0.11.
The most terrible fact about GFW is that it makes people forget they have a chance to access the other part of internet. Most netizens here don't even have a idea to cross it.