MACSOLU  Version 1.13 is the FINAL version that has been distributed as a Mac .app -- this version (1.15) is uncompiled and will be of NO USE to the vast majority of Mac users. Don't be confused when your download of 1.15 results in a folder full of misc. files.  
(Version 1.15)

TEKL  I tried several CHM Viewers for OS X. iChm, xCHM and ArCHMock are the only one which I can recommend.

But all are not perfect yet.

ArCHMock 1.1:

+ Fast

+ Nice Interface

+ Good HTML rendering (Webkit)

+ Highlighting search results in Text

+ Good keyboard support (Cmd+G etc.)

+ Bookmarks

+ Automatically locates the current page in the table of contents

+ Good search results (can be sorted by relevance)

+ Zooming can be resetted

+ Remembers the last position

+ Open source

- No Index

- No options for searching

- No "find in page"

- No toolbar button for print (but Cmd+P works)

- No tabs or multiple document windows

iChm 0.9.1:

+ Fast

+ Nice Interface

+ Good HTML rendering (Webkit)

+ Tabs

+ Auto-update feature

- No Index

- Bad keyboard support (no Cmd+G)

- No options for searching

- You habe to manually 'locate' the current page in the table of contents

- Only searchs for words (no partial search)

- No home button (and no hotkey for that)

- Because of the small tabs its hard to get the title of the current page (which is not shown in the window title)

xCHM 1.13:

+ Contents/Index/Results on left side

+ Searchable index

+ Options for searching in titles only or partial

+ Automatically locates the current page in the table of contents

+ Bookmarks

+ Open source

- Ugly interface

- Bad HTML rendering

- Does not support custom context menus (like in SelfHTML)

- Slow (scrolling)

- Search results are always sorted alphabetically

- No tabs or multiple document windows

- The binary of the Mac version won't be updated anymore

At the moment ArCHMock has the best usability for me.  
(Version 1.13)

THEWHITERABBIT  Unfortunately, I no longer have access to the MacMini machine I've been connecting to build xCHM. If you need pre-compiled xCHM binaries that you can drag-and-drop to install, I will continue to create them free of charge, provided that I manage to raise enough money to buy a cheap Mac machine to work on. If you would like to donate, you can use the "Support this project button" at the bottom of any page from http://xchm.sourceforge.net. All you need is a SourceForge.net account (which is free), and a PayPal account. The minimum donation allowed by the SourceForge.net system is $5, and I need to raise about 800 EUROs for the cheapest MacMini machine available here.

This is, of course, if you prefer to have pre-built universal binaries. The source code is still available for free, and it is obviously possible to make Mac builds.  
(Version 1.13)

RAIMONDI  It worked fine the first time I use it, after that I only get the splash window and can't open anything else. Any idea? it seems to be the best (unique)alternative to read CHM files...  
(Version 1.13)

BURRO  Worked beautifully in earlier versions. Arghh! I threw them away on two machines before trying 1.9... which does not work at all, except to open its own splash page.

I've tried it out on a 1.33MhZ G4 iBook, a brand-new Intel iBook, and 2 G4 733MHz towers. Same on each.

Thanks for your continued efforts, Rabbit!  
(Version 1.9)

THEWHITERABBIT  I've made a new build with the Unicode support disabled (my theory is that's what caused the crashes). Of course, I could be wrong. Please test it on i386 and let me know. You can get it from here:

http://prdownloads.sourceforge.net/xchm/xchm-1.9a-universal.dmg?download  
(Version 1.9)

THEWHITERABBIT  I've built an universal binary of xCHM for version 1.9. Not sure if it works properly on i386 though, I could only test it on a PPC-based machine. Thought you might be interested in that. Cheers.  
(Version 1.8)

THEWHITERABBIT  Yeah the 1.3 version shown by get info is a slip-up (heh, sorry). Please update your links to the latest version (1.5-2) which is even friendlier for Mac OS X users (no more warnings if the locale is not set to default, toolbar buttons added for 'find in page' and 'copy selection', and now Cmd-C also works.  
(Version 1.5)

KOBALT  hmmm, the file that downloads when i click on the xCHM v1.5 link appears to be v1.3 (when checked with 'get info') ... what's up with that?  
(Version 1.5)

TEKL  Doesn't show images with SelfHTML 8.1.1, SelfHTML 8.0 works. HTML-Rendering is not perfect.  
(Version 1.5)

WLESTER67  The file will not let me download, or if I download the link, it will not mount.  
(Version 0.9.0)

THEWHITERABBIT  Hello.

As the old xCHM Mac OS package seems to have been orphaned, there's a new binary of xCHM built for Mac OS X 10.4 available for download on the SourceForge page.

The link is:

http://sourceforge.net/project/showfiles.php?group_id=87007&package_id=171033

Cheers.  
(Version 0.9.0)

ANONYMOUS  please backup your claims with reasons  
(Version 0.9.0)

ROB  You can find it at:

http://www.dur.ac.uk/durmac/index.php?pageid=software_uni  
(Version 0.9.0)

ANONYMOUS  the download link is broken.. please fix it.  
(Version 0.9.0)

RICH  I'm torn between this and chmox - the other one is faster and way smaller. xCHM is huge and slow, but offers searching and bookmarking.

Hm. A collaboration would produce a great package...  
(Version 0.9.0)

D33CH  Very nice... I wanted to compile myself but this is allot easyer. Many thx to the coders  
(Version 0.9.0)

FART BREATH  Does exactly what I needed.

Dude, you rock!  
(Version 0.9.0)

FRED  I need this program but the url is broken  
(Version 0.9.1)

MIKKO LEVANEN  Great app..!! Installation was a clean shot and app works without problemz Many thanks for the coders.  
(Version 0.9.1)

JEDIK  Hmmm. Download link is broken: file not found.

This version fixes the font problem?

Kudos  
(Version 0.9.1)

ANONYMOUS  Unfortunately, in this new version the pop-up menus of the font preferences don't work :(  
(Version 0.9)

ANONYMOUS  Having tried other OS X .chm viewers without success, I was surprised and delighted when this little app blinked open immediately and displayed the files I needed to access. I really like that it doesn't just translate the .chm docs into a pile of .html files, too. Thanks!!  
(Version 0.8.10-2)

J J  I prefer a new app that just came out called CHM Viewer. Much smaller in size, faster, and better font rendering. It's $5, but worth every penny.  
(Version 0.8.10)

ANONYMOUS  Doesn't seem cto work on Jag ... (even Disk Utility "strikes out" while opening the disk image ... there's something wrong!) ... I'm sorry about this ... I'd like this app :(  
(Version 0.8.10)

ANONYMOUS  Works great! Thanks for putting getting this binary out for us double-clickers. I could not coax panther and fink into compiling it for life of me.  
(Version 0.8.10)