You could have downloaded NiniX 1.7 for Mac from our application library for free. The application is included in Productivity Tools.
From the developer:
MacOS X editor for the Lotus Notes Preferences file (more commonly known as the "Notes.INI" file on other platforms). Unlike other Notes platforms, the file on the Mac is not a text file and can NOT be edited with a regular text editor.
You may want to check out more software for Mac, such as Synpathy, T-Styles or WristRest, which might be similar to NiniX.