Tamil Script Code for Information Interchange
TSCII (Tamil Script Code for Information Interchange) is a coding scheme for representing the Tamil script. The lower 128 codepoints are plain ASCII, the upper 128 codepoints are TSCII-specific.
TSCII encodes the characters in visual (written) order, paralelling the use of the Tamil Typewriter.
Unicode has used the logical order encoding strategy for Tamil, following ISCII, in contrast to the case of Thai, where the visual order encoding grandfathered by TIS620 was adopted.
The government of Tamil Nadu endorse its own TAB/TAM standards for 8-bit encoding and other, older encoding schemes can still be found on the WWW.
The free etext collection at Project Madurai uses the TSCII encoding, but has already started to provide Unicode versions.