rtf In its original conception, the .rtf format was a specification for formatting text and graphics principally designed to facilitate the interoperability of documents and text between Microsoft document processing applications. It eliminated the need for specialized translation software required to open documents in different versions of MS-DOS, Windows, and Macintosh. The specification is a proprietary filename format first developed by Microsoft in 1987 to be supported in Microsoft word 3.0 and all versions of Microsoft Office Word thereof. The latest revision, version 1.9.1, was released in 2008 and also marked the end of any further enhancements to the specification by Microsoft. Through unformatted text, control words, control symbols, and groups, a piece of text can be encoded into an .rtf format. All RTF readers then process .rtf formats by separating and acting on control information disparately from the actual text in the document. Though the RTF specification is proprietary asset of Microsoft, several non-Microsoft programs support both reading .rtf documents and creating .rtf. Microsoft Office Suite is still however the most dominant application associated with this specification.
lit The .lit filename extension, short for literature, is a proprietary filename extension of the eBook file format LIT developed by Microsoft. The format was initially released in 2000 and at the time was only compatible with Microsoft Reader. Though DRM support was one of the strong selling points of the LIT format, wide spread DRM circumvention discounted its utility in favor for competing open formats. This among other reasons caused Microsoft to officially discontinue support for the format by 2011 and cease further sales of eBooks based on the format completely by 2012.