This technology eventually became COM (and COM+ and DCOM, led to the.
It was popular in the 1990s as a way to allow users to 'embed' content from other programs into Word documents, PowerPoint presentations, etc - this is what happens if you copy cells from an Excel spreadsheet and paste into a Word document, then double-click to edit it in-place. OLE components are small binary programs that are loaded into an existing process (usually office/'productivity' programs) which then display an inline UI. It was a rebranded, cut-down version of Design Science's MathType editor.
The messages referring to 'Equation 3.0' is shorthand for the 'Microsoft Equation Editor' which was an OLE component.
