SURFSPIRIT  Fast and the following feature is a must for me "Save whole file to PDF"

Great App! :)  
(Version 1.4)

RICHOZ  Simple and to the point. Great app!  
(Version 1.3.2)

MLBKXBX  I like. When i used linux i couldn't find any chm viewer worthy of actually using. So i simply didn't read chm files. There are some excellent chm's out there though so you really want a good chm viewer (php manual comes to mind). Ichm has got everything i need.

Looks, search feature, bookmarks, tabs, stability. It can only get better from here!  
(Version 1.4.2)

HERLITZ  Does everything it's supposed to. All + here!  
(Version 1.4.1)

TERRYANDTAOTAO  Among iChm, xCHM chmox and ArCHMock, iCHM is the the only one I would recommend.

I know it only took the coder several days to finish it. Really appreciate it. It's good to see more Chinese developers write high quality opensource programs.  
(Version 1.2)

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 0.9.1)

GBK  OK ! now all is good on MU ! really reactive :]  
(Version 0.9.1)

GBK  ok, i've missed sthg : "Intel only"...  
(Version 0.9.1)

SCOTTDB  Perfect CHM reader.

Cocoa, tabs, fast, simple interface, SEARCH!

Well done. I'll be donating shortly.  
(Version 0.9.1)

LIBIN PAN  A great chm reader! Simple and very fast. Tab view is a truly innovative!  
(Version 0.9.1)