Digital Tibetan (digitaltibetan.org) was a site with lots of useful information about Tibetan word processing, Unicode fonts and dharma technology.
Unfortunately, the site shut down in November 2021.
The Conversion Tools have now moved here:
Calendar converter between Tibetan and Western calendars. Includes calculation of special days for practitioners according to the Tibetan calendar.
You can still access the wealth of information about Tibetan dictionaries, configuring computers and mobile devices for Tibetan computing, and working with Tibetan texts, on the Wayback Machine's archive of DigitalTibetan.