Also see http://attendance.gov.in/ -- This is such a beautifully designed website that it blows my mind that the Government designed it!
Our startup ClearTax ( http://cleartax.in ) is made possible by the APIs of the Indian IRS.
The APIs aren't completely open but the registration process is not very onerous. The most interesting aspect is that the Indian IRS is keen on improving the APIs. When we make bug reports, they usually push fixes within 48 hours which is almost unexpected from the Government! Not everything is great but its one of the most advanced tax APIs in the world imo. The bug reporting process is a bit broken, but after the bug was reported they called us back and gave us information about the fix!
I am also deeply optimistic about India's progress in the next decade because of the new PM and the strong focus on development. See also: http://www.makeinindia.com/ a new initiative by the Government to get entrepreneurs building in India.