A fully-functional Babbage Difference Engine? That's been done and duplicated
. But the even more ambitious Babbage Analytical Engine? That's another story completely. Devised by mathematician Charles Babbage in the 1830s, the Analytical Engine can be considered to be the first programmable computer -- or at least the first notion of one -- but Babbage's plans for it were never finished, and the device itself (which would fill a room) was never built. That didn't stop computing pioneer Ada Lovelace from designing a programming language for it, though. Now a team of researchers from the Plan 28 group in the UK have begun work on a massive undertaking to finally bring Babbage's invention to life -- a project that's expected to take upwards of ten years and cost millions of dollars. In addition to a story on the project by John Markoff, the New York Times
also has a helpful overview of the machine itself at the source link below.