Although the ideal choice of format while designing a file that contains Help topics is CHM, it has a number of limitations not to mention, in certain circumstances. The Microsoft Compiled HTML Help (CHM) file format, on the other hand, is not as universal. It is one of the most commonly used formats today for the creation of almost any document-based media. Although PDF was originally an Adobe proprietary format, it has recently been published as an open standard. PDF is an acronym for Portable Document Format, and files of this format have been in circulation since 1993. It is not possible to be a frequent computer, laptop, or even smartphone user, and not have heard about the PDF file format. This problem, however, can be worked around by opening the file’s “Properties” window and unblocking the file. Each version handles CHM files differently, and hence sometimes, invariably, it may not be possible for some computers to open certain CHM files. chm file, one has to 'unblock' it in the file's properties ('Properties'–'General'–'Unblock').īeside the native support in Windows (since Windows 98/NT), there are also multiple Windows and non-Windows tools that can open CHM files and display, edit, or convert their contents.Since Windows 98, when the CHM format made its first appearance, a handful of newer versions of Windows along with their service packs have been released. chm files have the 'ITSF' signature in their header.ĬHM files downloaded from the Internet or supplied with third-party applications will often fail to open properly on Microsoft Windows (Vista and later), as they are blocked by the Windows security system by default. CHM files use the LZX compression algorithm. The file contains a set of HTML pages, hierarchically interconnected with an index and cross-referencing hyperlinks.

chm file is a help or e-book file in the CHM format. CHM retains its legacy status, having given way to the newer MAML format.Ī.

CHM is a Windows-specific format, developed by Microsoft and previously intended as a single standard format for Microsoft Windows help files. chm filename extension is associated with the Compressed, or Compiled HTML (CHM) file format and type.

Open chm file