pdf The .pdf file format extension was developed by Adobe systems in 1993 as a means of presenting documents in a consistent manner across different platforms, hardware, operating systems, and applications. The format was not released as an open source document format until 2008, though minimal proprietary technologies still controlled by Adobe Systems exist in the format. Every .pdf document carries with it the necessary meta information required to properly reconstruct the text, fonts, and graphics used to produce the document. This ensures that documents will be viewed in exactly the same way the author intended regardless of the device used to open the document. From conception to date, Adobe Systems has continued to support the format adding features with every iteration of the standard including hardened algorithms for document encryption and privacy. Today, many freely available readers exist allowing you to open and view .pdf documents and create or convert other file formats such as .jpeg and .doc into .pdf documents.
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.