I studied at PUC-Rio and I met Roberto Ierusalimschy (the main author of Lua) when he was teaching a course on semantics. I once asked him if I could send a PR about a feature I wanted in the language and he said something that I never forgot: "Yes, but I won't use your code. I love that people send me ideas, but I actually enjoy coding... so I will gladly take your suggestions, though I will write it myself."
He then explained this "dictatorial" behavior is what allowed him to keep the implementation simple and concise over the years. At the time he boasted about the source code being less than 8K LOC, though it has likely increased in recent versions. (I think it was around version 3.) I'd recommend taking a look at the source code, it's truly a C masterpiece.
I'm currently a PhD candidate at PUC-Rio. For context, there's a 'meet the researchers' round of seminars during the first semesters mainly targeted towards Master's students (so they can choose an advisor).
Prof. Ierusalimschy's was one of the most interesting seminars in my first year. His passion is apparent in the way he talks about Lua's history and current development. Unfortunately I haven't taken any courses with him
As a side note, it's nice to see folks from around here on HN
I second that recommendation about the Lua source code. Back in the 00s I built a kiosk management system in Lua, C, and C++ and it was a delightful language to work with and I found myself reading through the sourcecode a fair bit, always impressed.
He then explained this "dictatorial" behavior is what allowed him to keep the implementation simple and concise over the years. At the time he boasted about the source code being less than 8K LOC, though it has likely increased in recent versions. (I think it was around version 3.) I'd recommend taking a look at the source code, it's truly a C masterpiece.