If you would rather do it yourself by hand, the following is my original post containing instructions for manually installing the Cider version, upon which the mystonline-cider port in MacPorts is now based:1. Download the old Mac client (http://archives.gametap.com/static/uru-client/mac/mac_myst_setup.dmg) from Gametap, mount the disk image, and copy Myst Online.app to your Applications folder -- or, if you played MO:UL years ago and saved a copy of the app, use that, because it already contains most of the assets the game needs and you won't have to download them again.2. Replace UruLauncher.exe in /Applications/Myst Online.app/Contents/Resources/Myst Online.app/Contents/Resources/transgaming/c_drive/Program Files/Uru Live with the new copy.Where do you get the new copy of UruLauncher.exe? I got it by downloading the current MO:ULagain installer for Windows and running it in Wine. This will install UruLauncher.exe into ~/.wine/drive_c/Program Files/Uru Live and you can copy it from there into the Myst Online application. If installing Wine just to get UruLauncher.exe is too much trouble, you can download UruLauncher.exe here(http://distfiles.macports.org/mystonline/) (as a zip file, which you should extract before proceeding).Once you have the new UruLauncher.exe, how do you put it inside Myst Online.app? You can do it in the Finder: In the Applications folder, Control-click Myst Online.app. In the resulting window, go into Contents, then Resources, then Control-click again on this Myst Online.app. Again navigate into Contents > Resources > transgaming > c_drive > Program Files > Uru Live. Drag the new UruLauncher.exe from wherever you put it on your hard drive into this folder and replace the old one.This worked for me. After launching Myst Online.app, it downloaded a new patcher, then downloaded about 400MB of updates (slowly), then let me log in (very slowly) and eventually get into the cavern. (If you used a fresh Myst Online.app from the Gametap disk image, it'll need to download a lot more than that.)