From Tamil Bible:
Tamil Bible software helps to read the Bible in Tamil. Read and have a blessed time.
If you can't view in tamil fonts (typically in windows XP) you have to make sure that you go to control panel and click on the "Regional language Options". Go to Language Tab and check the box that says "Install files for complex script and right-to-left languages(including Thai)". It opens with daily bible reading chapter as it appears in the Tamil bible site (www.tamil-bible.com)