Inkscape and X11 issues...
Inkscape is an insanely cool open source vector graphic editor that uses SVG as its native file format. I installed it shortly after reading about it with no problem, except that when it starts up it complains about X11 not being installed.
Apple provides a download, X11User, that will set things up if you haven’t already. The download page says something about a version on the Tiger DVD installation disk, but I assumed the download would work as well. (After the fact I see the System requirement is 10.3.8 – 10.3.9)
Ouch, don’t do it. If you install X11User from Apple’s website it decides your OS X version is 10.3.8 and iTunes and other applications won’t work anymore! I tried to figure out what files I had blindly installed, but the damage was done. I tried several efforts at getting Software Update to work, but it felt my Panther 10.3.8 system was up to date :-(
Long story short, here is a good file to know about: /System/Library/CoreServices/SystemVersion.plist It contains the version of OS X that most of your applications will care about, including Software Update. I altered the 10.3.8 to 10.4, then ran Software Update and Software Update got everything repaired to 10.4.8. As a special bonus the X11 stuff continued to work, so I am now Drawing Freely, with Inkscape.