This is a snapshot of linux 2.6.12 kconfig as washed through busybox and further modified by Rob Landley. Note: The build infrastructure in this directory is still GPLv2. Cleaning that out is a TODO item, but it doesn't affect the resulting binary. Way back when I tried to push my local changes to kconfig upstream in 2005 https://lwn.net/Articles/161086/ and 2006 http://lkml.iu.edu/hypermail/linux/kernel/0607.0/1805.html and 2007 http://lkml.iu.edu/hypermail/linux/kernel/0707.1/1741.html each of which spawned long "I think you should go do this and this and this but I'm not going to lift a finger personally" threads from the kernel developers. Twice I came back a year later to see if there was any interest in what I _had_ done, and the third thread was the longest of the lot but no code was merged as a result. *shrug* That's the linux-kernel community for you. I had an easier time than the author of squashfs, who spent 5 years actively trying to get his code merged, finally quitting his job to spend an unpaid year working on upstreaming squashfs _after_ after every major Linux distro had been locally carrying it for years. No really, here's where he wrote about it himself: https://lwn.net/Articles/563578/ This code is _going_away_. Rewriting it is low priority, but removing it is a checklist item for the 1.0 toybox release. This directory contains the only GPL code left in the tree, and none of its code winds up in the resulting binary. It's just an editor that reads our Config.in files to update the top level .config file; you can edit they by hand if you really want to.