Hopefully by the time you read this, someone at Apple or XQuartz would have fixed this issue. This workaround is just posted here in case anyone else finds it useful to be able to use X11 apps on their second monitor once again after upgrading to Mavericks, and doesn't mind jumping through a few hoops. This is hardly a permanent solution, nor is it guaranteed to work under all versions of OS X, XQuartz, etc. If you're here to try to get Inkscape or other X11 apps to work in Mavericks in the first place, try this post first: Disclaimer: You know what the following terms mean: 'dock', 'desktop', 'mission control', 'spaces', 'X11', 'XQuartz', 'secondary click'.Advanced: Try resetting or reinstalling the X11 app, or editing its config file?) You haven't already dragged the application window out of bounds in one of your spaces (in which case you'll need to figure out how to reset its position first - can't help there at the moment since each app handles its position in different ways.'Displays have separate Spaces' is checked under: System Preferences -> Mission Control.XQuartz version is XQuartz 2.7.4 (xorg-server 1.13.0) or under (haven't tested it with newer versions, and newer versions may fix this problem rendering this workaround pointless).The OS X Team nor the XQuartz team have not addressed the issue yet (test this out to make sure that you're not using a workaround when things actually work).The following are the conditions under which this workaround worked: This workaround only works under very specific conditions right now, and there is no guarantee that it will work under other conditions. A better workaround is to simply turn off 'Displays have separate Spaces' in: System Preferences. Thus, I'd recommend not following it for the time being unless you're curious. Even if you get it to work, X11 programs will be riddled with bugs because of how Mavericks currently treats Spaces coordinates, gravity, etc., with XQuartz.

This workaround was written as a reminder for myself. I don't want to turn off 'Displays have separate Spaces.' I've upgraded to OS X Mavericks and I can't place apps such as Inkscape on my second monitor any longer.

Inkscape where is xquartz