In order to be able to use MkIV and Luatex I started, as a MacTeX-user, by updating ConTeXt (*MacTeX*http://wiki.contextgarden.net/index.php?title=MacTeX&action=edit&redlink=1: You need to updatehttp://wiki.contextgarden.net/Running_Mark_IV#Updating_ConTeXtConTeXt first.), following instructions on http://wiki.contextgarden.net/Running_Mark_IV#Updating_ConTeXt The command as given (copied and pasted in terminal) does not work: everything fails: Operation not permitted. Redoing it as Sudo does the job. But then: “luatools --generate” gives: -bash: /usr/texbin/luatools: Permission denied, “sudo luatools --generate” gives “luatools: command not found”. So I cd-ed to /usr/texbin, gave the command “sudo chmod 755 luatools” and then “luatools --generate” and got: LuaTools | error unable to identify cnf file LuaTools | no cnf files found (TEXMFCNF may not be set/known) LuaTools | LuaTools | runtime: 0.002 seconds But worst of all is that after all this I could not use MkII any more: Older files that before updating had been nicely typeset couldn’t be processed anymore: permission denied. I tried “sudo chmod 755” on texexec and on texmfstart but that did not help. So in the end I reinstalled MacTeX 2008 and I was back at where I started. The least one can say is that the updating instructions on contextgarden do not work in all circumstances. In all fairness, everybody is warned: “Note that this is a quick-and-dirty way to upgrade TL. Use at your own risk. One should be able to update in a more elegant way.” But now what? Lots of MacTeX-users must have successfully updated ConTeXt. Can anybody disclose a more elegant way that worked for them? Especially one that does not render the existing ConTeXt useless by meddling with permissions. Just for the sake of completeness, I use an Intel iMac under OSX 10.5.6. Thanks in advance, Robert Blackstone