Transliteration bookmarklet is a small piece of code that you store in your browser. Once stored, you can type in Malayalam in any text box on any web-site of your choice. It works on Google web-sites as well as other web-sites.
Click here to get the transliteration bookmarkle
NB : You should install malayalam font to use this option.
For other languages, use the appropriate link: Arabic Bengali Gujarati Hindi Kannada Malayalam Marathi Nepali Tamil Telugu