Because MathType 6.9b is abandonware (no longer sold or supported by the publisher), legitimate acquisition is tricky. It was originally sold via download on the Design Science website. Today:
Users on 6.9b are encouraged to upgrade to MathType 7, which offers:
While 6.9b is excellent, time marches on. If you cannot get it running, consider these alternatives:
MathType 6.9b is an older release of the MathType equation editor — a desktop tool for creating mathematical notation that can be used in word processors, presentation software, and web pages. Below is a concise blog-style overview you can use or adapt.