Get this add-on/ extension:
https://addons.mozilla.org/firefox/2994/
A utility for typing in Tamil language. It will be ideal for Tamil bloggers.
Tamilkey will support most of the popular keyboard layouts used among Tamils. Currently Tamilkey supports Anjal, Tamilnet99, Bamini, Old and New Tamil typewriter keyboard layouts.
Prerequisite:
Your computer should have at least one Tamil Unicode font.
Steps for usage:
1. Install the Tamilkey extension and restart the Firefox.
2. Keep the cursor in any text field in the browser and press the following Hot keys for the respective keypad maps start typing in Tamil language!
Alt+F8 => Anjal
Alt+F9 => Tamil 99
Alt+F10 => Bamini
Alt+F11 => Old Typewriter
Alt+F12 => New Typewriter
To switch back to English typing, Press F9
You can also assign different Hot keys to your convenient key combinations using the “Options” menu of this extension.
Happy Tamil Typing !!!
Mugunth
http://mugunth.tamilblogs.com
http://mugunth.blogspot.com
http://thamizha.com
