This discussion has seemingly diverged in two different directions, and I'd like to clarify exactly what the concerns are. The discussion was initially about moving xmonad.hs to XDG_CONFIG_HOME. This is essentially a bike shed issue: some prefer $HOME/.xmonad/xmonad.hs and others prefer $HOME/.config/xmonad/xmonad.hs. I prefer the former, and I haven't seen any convincing arguments for the latter, so we're going to stick with $HOME/.xmonad/xmonad.hs. Brandon Allbery presented another concern about data files that xmonad writes, such as the cached executable and prompt's history. It is possible that there are race conditions with concurrent readers/writers that may cause corruption. One potential workaround for this is to append the hostname to XDG_DATA_HOME (or perhaps XDG_CACHE_HOME). It is important to note that this is orthogonal to XDG_CONFIG_HOME and only involves internal xmonad files that the user typically doesn't interact with. I don't think this solution is the right direction. There are still potential problems with multiple instances of xmonad on the same hostname, and it seems to be non-standard (or at least not expected) use of the XDG Base Directory Specification. If the potential of writing corrupted files is still a concern, I recommend that someone create a bug on the bug tracker and/or a new thread on the mailing list. I also suggest that we avoid mentioning XDG_CONFIG_HOME at all in that discussion, because it is orthogonal and tends to result in bike-shed arguments. Cheers, Spencer Janssen