The CHM file format was developed by Microsoft and first released along with Windows 98 and the format continues to be supported. This file format superseded WinHelp. CHM files grew in popularity due to the fact that they are fully compatible with a web browser which can be found on all computers. The vulnerability of this file type has been highlighted widely due to the ability for certain controls to be executed by the file.
A .chm file comprises of a number of HTML pages and an Index. The format supports 28 different language types. The file provides functionality such as compression, merge and search. Just like a HTML page, the file can be composed of a variety of tags and images to enrich the content of the help files.
Associated programs
Beyond CHM Internet Explorer Microsoft Reader Mozilla Firefox
The .oeb file extension was created for use in accordance with the Open eBook Standard which was overseen by the Independent Digital Publishing Forum (IDPF). This is now a legacy format, having been superseded by the epub file type.
Based on XML, the oeb file defines how multiple sources should be ordered and arranged into a single electronic delivery for the user to consume. This means that there Is one file to be transferred between the vendor and customer rather than multiple files. The file type permits the use of DRM protection. The format was designed to be open and easily used by any online bookstore.