Viewing CHM files in Linux (With installation instructions for Ubuntu )

CHM or Microsoft compiled HTML Help is a format developed by Microsoft for online help . Most of the documentation in Windows platform is in chm file format , also these days most of the ebooks available on the internet are either available in the chm file format or pdf file format .

Now most of the distributions do not ship tools and libraries for viewing chm files by default since it is a proprietary format used by Microsoft Products , So if you want to read a ebooks which are in chm file format you have to install third party tools and libraries . In this short tutorial i try to describe how to install some of the tools for viewing CHM files on your Ubuntu desktop :

1. Gnochm

Gnochm is a gnome based chm viewer that has the following features : -

* Support for external ms-its links
* Full text search support
* Bookmarks
* Configurable support for HTTP links
* Integrated with GNOME2
* Support for multiple languages
* Support to open multiple files at once

To install gnochm issue the following command in the terminal window (assuming you have your repositories in order , if not read this article and set your repositories right )

sudo apt-get install gnochm

After installation gnochm should be installed properly , which you can even launch by typing in "gnochm" in the terminal window .

Gnochm

2. kchmviewer
If you are one of those who likes using KDE desktop environment you might like using a tool that uses KDE library instead of gnome one , and integrates better with KDE desktop .

A nice chm viewer for KDE desktop is kchm viewer :

Here is a text about kchmviewer taken from it's package file :

KchmViewer is a chm (MS HTML help file format) viewer, written in C++.
Unlike most existing CHM viewers for Unix, it uses Trolltech Qt widget
library, and does not depend on KDE or Gnome. However, it may be compiled
with full KDE support, including KDE widgets and KIO/KHTML.

The main advantage of KchmViewer is non-English language support. Unlike
others, KchmViewer in most cases correctly detects help file encoding,
correctly shows tables of context of Russian, Korean, Chinese and Japanese
help files, and correctly searches in non-English help files (search for
MBCS languages - ja/ko/ch is still in progress).

Completely safe and harmless. Does not support JavaScript in any way,
optionally warns you before opening an external web page, or switching to
another help file. Shows an appropriate image for every TOC entry.

KchmViewer Has complete chm index support, including multiple index entries,
cross-links and parent/child entries in index as well as Persistent bookmarks
support. Correctly detects and shows encoding of any valid chm file.

to install kchmviewer type in the following command in the terminal window :

sudo apt-get install kchmviewer

and after above step is completed you can launch kchmviewer by typing in kchmviewer in the terminal window

kchmviewer displaying a chm file

3. xCHM

XCHM is a chm file viewer , that is not bound to any desktop environment and could be used even in window manager like fvwm or xfce .

Here is text taken about xCHM from it's package file :

"xCHM is a viewer for Compiled HTML Help (CHM) files. It, can show the contents
tree if one is available, print the current page and do the usual history
stunts. It allows you to change fonts and search for text in all the pages of
the file, or in the pages' titles."

xCHM does not support JavaScript in books."

to install xchm issue the following command in the terminal window :

sudo apt-get install xchm

and then you can launch xchm by typing in xchm in the terminal window .

xCHM in action

4. Mozilla Firefox add-on to display chm files

Mozilla Firefox is a powerful platform and it can be extended to do a number of cool things by installing different plug ins and one really useful addon is a CHM viewer .

To install CHM reader addon go to the following site and click on install button , procedure after that is quite self explanatory owing to extremely easy interface of Mozilla Firefox .

After clicking install button you will find a dialog box like this just click the "Install Now" button in this dialog box

After installing you can easily open chm files from Mozilla Firefox , In the File submenu you will find a option of opening chm files .

File Menu in Firefox showing new option to open CHM file

Firefox rendering a CHM file

5. Okular

if you happen to install kde4 on your desktop , Okular is the new addition to the KDE desktop environment . Okular besides having ability to render pdf , djvu files can also display chm files flawlessly . Besides being based on solid KDE 4 libraries Okular allows one to add notes , highlight text etc . It is one of the most advanced document reader available on linux . To install KDE 4 with Okular read this article about how to install KDE 4 on Ubuntu i had written few weeks back .

Okular in Action :)

Article Written by : Ambuj Varshney (blogambuj@gmail.com)
(C) 2008 , For Linux On Desktop Blog (http://linuxondesktop.blogspot.com)