История изменений

https://reiser4.wiki.kernel.org/index.php/Why_Reiser4#Reiser4_and_upstream

Reiser4 and upstream
In contrast with its predecessor (ReiserFS, v3), Reiser4 was not accepted to the upstream Linux kernel because of political reasons. Later Edward Shishkin expressed an interest (*) to port Reiser4 to other operating systems, specifically, to FreeBSD, which is, according to his standpoint, «more open to academic researches». In this case it would be illogical to expect Reiser4 to be tightly integrated with some particular operating system. Thus, Reiser4 is developed as a standalone independent project (*). The archive of ports for upstream Linux kernels can be found at the project sites.

https://reiser4.wiki.kernel.org/index.php/Main_Page