Excerpts from "Version Control with Subversion" bellow nicely describe why MIME comes into our life.
"Various programs on most modern operating systems make assumptions about the type and format of the contents of a file by the file's name, specifically its file extension. For example, files whose names end in .txt are generally assumed to be human-readable; that is, able to be understood by simple perusal rather than requiring complex processing to decipher. Files whose names end in .png, on the other hand, are assumed to be of the Portable Network Graphics type—not human-readable at all, and sensible only when interpreted by software that understands the PNG format and can render the information in that format as a raster image"
"Unfortunately, some of those extensions have changed their meanings over time. When personal computers first appeared, a file named README.DOC would have almost certainly been a plain-text file, just like today's .txt files. But by the mid-1990s, you could almost bet that a file of that name would not be a plain-text file at all, but instead a Microsoft Word document in a proprietary, non-human-readable format. But this change didn't occur overnight—there was certainly a period of confusion for computer users over what exactly they had in hand when they saw a .DOC file"
"The popularity of computer networking cast still more doubt on the mapping between a file's name and its content. With information being served across networks and generated dynamically by server-side scripts, there was often no real file per se, and therefore no filename. Web servers, for example, needed some other way to tell browsers what they were downloading so that the browser could do something intelligent with that information, whether that was to display the data using a program registered to handle that datatype or to prompt the user for where on the client machine to store the downloaded data"
"Eventually, a standard emerged for, among other things, describing the contents of a data stream. In 1996, RFC 2045 was published. It was the first of five RFCs describing MIME. It describes the concept of media types and subtypes and recommends a syntax for the representation of those types. Today, MIME media types—or “MIME types”—are used almost universally across email applications, web servers, and other software as the de facto mechanism for clearing up the file content confusion"
"Various programs on most modern operating systems make assumptions about the type and format of the contents of a file by the file's name, specifically its file extension. For example, files whose names end in .txt are generally assumed to be human-readable; that is, able to be understood by simple perusal rather than requiring complex processing to decipher. Files whose names end in .png, on the other hand, are assumed to be of the Portable Network Graphics type—not human-readable at all, and sensible only when interpreted by software that understands the PNG format and can render the information in that format as a raster image"
"Unfortunately, some of those extensions have changed their meanings over time. When personal computers first appeared, a file named README.DOC would have almost certainly been a plain-text file, just like today's .txt files. But by the mid-1990s, you could almost bet that a file of that name would not be a plain-text file at all, but instead a Microsoft Word document in a proprietary, non-human-readable format. But this change didn't occur overnight—there was certainly a period of confusion for computer users over what exactly they had in hand when they saw a .DOC file"
"The popularity of computer networking cast still more doubt on the mapping between a file's name and its content. With information being served across networks and generated dynamically by server-side scripts, there was often no real file per se, and therefore no filename. Web servers, for example, needed some other way to tell browsers what they were downloading so that the browser could do something intelligent with that information, whether that was to display the data using a program registered to handle that datatype or to prompt the user for where on the client machine to store the downloaded data"
"Eventually, a standard emerged for, among other things, describing the contents of a data stream. In 1996, RFC 2045 was published. It was the first of five RFCs describing MIME. It describes the concept of media types and subtypes and recommends a syntax for the representation of those types. Today, MIME media types—or “MIME types”—are used almost universally across email applications, web servers, and other software as the de facto mechanism for clearing up the file content confusion"
