Years back, I had been of some help in readying a Kannada font for Mac OS X. It was a Mac OS X port of Kedage font. I had no Mac device with me then.
Through Sampada, I used to get several emails from Kannadigas around the globe requesting information about getting to read Kannada on devices running Mac OS X.
Things have changed a lot since then. Mac OS X now supports Kannada out-of-box although the font supplied is not the best available. If you end up buying the latest Macbook Air or Macbook Pro running 10.8 Mountain Lion, the rendering is quite good - except for few bugs in the fonts supplied out of box.
However, on Mac OS X 10.6 (Snow Leopard) and on Mac OS X 10.7 (Lion), I've tested and found that by using the Kedage font or Sangam MN (if you get a copy of that) you can get to read Kannada pretty fine. The rendering is close to flawless, except for few (negligible for the moment) issues.
Alright, that is about being able to read Kannada text on Mac. How about typing in Kannada?
This was something that many people have kept asking for a long time. I used to get many emails on Sampada that had queries about just this. I still keep getting email requests on how to achieve this on Mac OS X, so here's the status as I know it (and based on what I tried) and a workaround that has been quite a good option so far:
Apple provides a set of input methods out of box and there are two input methods available for Kannada on that list - Kannada and Kannada QWERTY. The input source Kannada is a take on NUDI or K P Rao method of input for Kannada. However, it doesn't work as it should. Kannada QWERTY is an implementation of Inscript keyboard layout which seems to work for most part, but I haven't had a chance to test it fully. These two methods are probably the most used in the journalism and media circles here in the state. The other popular input style or layout that is quite popular among Kannadigas is Baraha style (an adaptation of itrans modified to suit the Kannada users) which is not included in Mac OS X.
While the Nudi or K P Rao input source included does have bugs, these can be modified and adapted better using Ukelele. Ukelele is an excellent software to edit keyboard layouts and when I was trying to customise the Kannada input sources supplied with Mac, it was quite fun to work with. It is a good solution for preparing keyboard layouts, especially notations of Carnatic music. However, when I was trying to implement Baraha style or the adaptation of itrans, it was quite a time consuming effort to edit on Ukelele with several challenges in getting the key combinations to work.
Looking around for alternatives, I found Mac UIM. Mac UIM is a bridge of UIM - a quite familiar library for those who've tried or worked on input methods on GNU/Linux. Installing this provides the ability to use m17n library or the input methods available on m17n. This opened up the possibility of using those fine input methods available via m17n on GNU/Linux. I was delighted and quite surprised to see that it just got so simple all of a sudden when I found this! Having contributed a bit to Kannada on m17n also added to my delight. Adding to all that, UIM is quite stable on Mac. Apart from a bug on Mountain Lion where at times the settings app does not appear in System Preferences on a fresh install, based on the testing I could manage - things are pretty good. It also apparently changes the font preference. There's a workaround for the bug and for setting the font preference. So, happy times now typing in Kannada on Mac OS X!
Note: Sangam MN fonts do not get rendered fine on Firefox. Switching to Mac port of Kedage helps. Sangam MN fonts were initially released for iOS and they render quite well on that.