The website was "static", in pure HTML, for many years. Then it run with a lot of PHP code, on a design based on the Garland theme of Drupal, though at that time it did not run on a database.
The current server was built using Drupal and the nitobe theme. The header is from a picture of Malabar Hill taken (in a stormy day) by Pablo Ares.
The logo on the top-left is not an official logo of TIFR. The background is a blurred crop of a digital photo, done using gimp.