An even more extreme case of this is trying to bootstrap a compiler from the first version, e.g.: http://www.joachim-breitner.de/blog/748-Thoughts_on_bootstrapp

An even more extreme case of this is trying to bootstrap a compiler from the first version, e.g.: http://www.joachim-breitner.de/blog/748-Thoughts_on_bootstrapping_GHC http://www.joachim-breitner.de/blog/748-Thoughts_on_bootstra... """So it seems that besides GHC, only ever HBC was used to compiler GHC. HBC is a Haskell compiler where we find the sources of one random version only thanks to archive.org. Parts of it are written in C, so I looked into this: Compile HBC, use it to compile GHC-0.29, and then step for step build every (major) version of GHC until today. .... [M]ost of [HBC] is written in LML, and the LML compiler is written in LML."""